Unlocking efficient electrocatalytic removal of trace emerging contaminants via synchronized pollutant enrichment and electron delivery

Domain: physics
Published: 2026-01-06
Editorial outcome: major_revision

Abstract
Emerging contaminants (ECs) pose escalating global threats to water security and human health, driving urgent demands for advanced remediation; however, electrocatalytic elimination of trace ECs remains intrinsically constrained by dual limitations: diffusion of ultra-dilute pollutants and sluggish interfacial electron transfer. Here, we introduce an integrated strategy that synergistically regulates mass transport and electron transfer using a conductive molecularly imprinted polymer (c-MIP) electrode operated in a charging-discharging mode. The c-MIP selectively enriches trace ECs at the electrode surface, overcoming diffusion barriers. Critically, its capacitive properties enable temporal control of electron delivery, synchronizing the electron transfer rate with the intrinsic oxidation kinetics of ECs during the discharging phase. This synchronization achieves near-complete EC degradation with 90% lower energy consumption than conventional direct-current electrocatalysis, while maintaining 99% (95% Confidence Interval: 98.0%−100.0%) efficiency over 1,000 cycles. Our work delivers an energy-efficient electrocatalytic platform with operational stability for advanced trace organic pollutant remediation.

Introduction
With the explosive growth of emerging contaminants (ECs) stemming from industrial production and consumer activities, their potential ecological toxicity has become a significant global concern1–5. Although ECs are typically present at trace concentrations, their risk quotients often exceed safety thresholds due to extremely low Predicted No-Effect Concentration, resulting in high ecological risks6–9. In wastewater treatment plants, conventional approaches such as biodegradation and adsorption/membrane filtration are commonly employed for EC removal. However, these methods face significant limitations, including low degradation efficiency and the inability to achieve complete mineralization10,11. Electrocatalysis has emerged as a reliable and adaptable means for advanced water purification12,13. However, its practical application in EC removal is hindered by high energy consumption14. In most cases, substantial overpotentials are required to achieve a satisfactory removal rate, which in turn leads to exponential growth in both energy consumption and carbon emissions15. These challenges underscore the urgent need for innovative electrocatalytic strategies that address both energy efficiency and degradation efficacy.

A key bottleneck in current electrocatalytic systems (Fig. 1) arises from the extremely low concentrations of ECs in wastewater, typically in the ppt-ppm range16–20. Under such conditions, mass transfer of EC molecules from the bulk solution to the electrode surface becomes rate-limiting. Enhancing local reactant concentrations at the electrode-electrolyte interface is therefore critical. Moreover, even if the limitation in mass transfer was overcome, the sluggish electron transfer kinetics in EC degradation also impede performance according to our results. Conventional direct current (DC) electrocatalysis typically expends significant energy overcoming electrode polarization and sustaining undesired side reactions, leading to poor overall energy efficiency21–23. Thus, breaking the limitations in both mass transport and electron transfer simultaneously is the key to improve the energy efficiency of electrocatalytic EC removal.

Selective enrichment of ECs at the electrode surface represents a promising strategy to alleviate mass transport limitations. While many existing strategies focus on overcoming mass transport limitations through selective enrichment, the equally critical constraint of electron transfer kinetics has been largely overlooked. Conventional approaches such as interfacial functionalization or pre-concentration membranes offer limited benefits in enhancing electron transfer process. The integration of molecularly imprinted polymers (MIPs) and non-potentiostatic electrochemical operation mode offer a compelling solution by simultaneously addressing both challenges. In addition to the high selectivity of MIPs that increases local concentrations of ECs24,25, their porous structures also contribute considerable capacitive properties, allowing them to store electrical energy in the form of non-Faradaic charge within the electrical double layer26–30. Beyond the considerable capacitance, certain long-lived organic radicals formed during catalysis may also contribute to continued contaminant degradation24,25,31. Effectively harnessing this energy presents a novel route to enhance performance and reduce energy input. Therefore, when integrated with appropriate electrochemical operation modes, MIPs can function as electrochemical reservoirs that accumulate charge during DC polarization and gradually release it during the discharging stage. This controlled energy release aligns well with the inherently slow kinetics of EC degradation, thereby enhancing electron transfer efficiency and reducing overall energy consumption.

In this work, we introduce a “charging-discharging” electrocatalytic strategy coupled with a conductive MIP (c-MIP) to synergistically regulate the electron delivery and optimize energy utilization during EC degradation. Using azithromycin (AZN) as a model contaminant, the system achieves significant mineralization in both charging and discharging phases, delivering ~90% energy savings compared to conventional DC electrocatalysis, as confirmed by in-situ CO2 evolution monitored via differential electrochemical mass spectrum (DEMS). Additionally, the system exhibits excellent operational stability, maintaining 99% performance after 1000 cycles. Overall, this work provides a dual-mode electrocatalytic platform that synergistically integrates molecular imprinting and pulse-like energy delivery, offering a scalable, selective, and energy-efficient solution for real-world EC removal in water treatment systems.

Results
Preparing the c-MIP
A thiophene-based c-MIP was prepared using functional monomers as shown in Fig. 2a. It is worth noting that benzo[1,2-b:5,6-b′]dithiophene-4,8-dione (Bth-BQ) was adopted as a redox-active catalytic center to facilitate the direct electron transfer. The electron microscopy images (Supplementary Fig. 1) supported the successful synthesis of c-MIP. To avoid the use of organic reagents like methanol and acetic acid in traditional template extraction32,33, multiple electrochemical extraction methods, potentiostatic, cyclic voltammetry, and redox pulsing, were explored. Then Fe(CN)6 3−/4− was adopted as the redox probe to evaluate the amount of AZN combined with MIP before and after each treatment, as the absence of AZN would improve the accessibility of electrodes to Fe(CN)6 3−/4−. As displayed in Fig. 2b, the reduction peak of Fe(CN)6 3− was suppressed before extraction due to the occlusion of surface sites by AZN. The reduction peak rose after all 5 procedures, and the redox pulses switched between 1.2 V for 30 s and −1.0 V for 30 s (Fig. 2c) performed best as the peak current boosted most. Electrochemical impedance spectroscopy (EIS) corroborated these findings. The Nyquist plots of the MIP (PBth-BQ)@GCE before and after pulsed extraction differed a lot (Supplementary Fig. 2a). By fitting parameters with the equivalent-circuit model shown in Supplementary Fig. 2b, the charge transfer resistance (Rct) of MIP dropped from 4358.0 ± 98.8 Ω to 60.9 ± 7.0 Ω after extracting AZN templates by the redox pulse, indicating a more accessible interface for electron transfer. Also, the fitted n dropped from 0.92 ± 0.01 to 0.63 ± 0.02 after extracting templates, indicating enhanced surface porosity34.

To further confirm the successful imprinting and removal of AZN, Fourier-transform infrared spectroscopy (FT-IR) analysis was conducted. A prominent absorption at ~1630 cm−1, corresponding to the C=O stretching of AZN35, was present in the MIP before extraction and disappeared following redox pulsing (Fig. 2d). Upon rebinding AZN, the C=O peak re-emerged, verifying the selective recognition capability of the MIP without structural degradation. As revealed by contact angle measurements, an improved hydrophilicity was achieved after polymerization, decreasing from 89.1 ± 3.9° to 43.2 ± 2.3° (Fig. 2e), which is expected to promote aqueous-phase contaminant capture36. Also, a thin and uniform MIP layer is crucial for the selective recognition and rapid adsorption of target ECs, as the uptake process primarily follows a Langmuir-type mechanism involving monolayer adsorption onto a limited number of imprinted sites. An excessively thick MIP layer may hinder the direct electron transfer between the captured ECs and the underlying electrode surface by increasing charge transfer resistance and limiting access to electroactive sites. Atomic force microscopy (AFM) analysis confirmed a uniform film morphology with a thickness of approximately ~7 nm (Fig. 2f, g), indicating a favorable two-dimensional configuration for electron transport37,38. The AZN adsorption isotherm on c-MIP (Supplementary Fig. 3) showed a maximum adsorption capacity (qm) of 16.35 μg/cm2 and demonstrated a Langmuir-type adsorption behavior (R2=0.99), which indicated a single layer adsorption. As a result, the adsorption kinetics tests demonstrated the rapid and high-capacity uptake of AZN by the MIP (PBth-BQ)@GC electrode that it adsorbed 8.4 times more AZN than bare GC in 10 min and 6.8 times more in 240 min (Fig. 2h).

Identifying electron transfer limitation of ECs beyond mass transport
To identify electron transfer behaviors of typical ECs in electrochemical oxidation, we employed Fourier-transform alternating current voltammetry (FTacV) to evaluate five typical ECs: AZN, carbamazepine (CBZ), tetracycline (TET), amoxicillin (AMX), and ciprofloxacin (CIP). The ECs are dripped on the glassy carbon electrode (GCE) to avoid diffusion limitation. The total current, AC voltammetry (ACV), direct current voltammetry, and 3rd harmonic components extracted from FTacV measurements on a bare GCE in the presence and absence of each EC were displayed in Supplementary Figs. 4–9. Generally, the 3rd harmonic ACV excluded the contribution of non-faradic current and decoupled overlapping electron transfer processes, thereby offering deeper insights into the redox behaviors of these ECs. Notably, the 3rd harmonic ACV current responses recorded at varying frequencies (0.19–47 Hz) suggested the difference in electron transfer rates of these ECs39,40.

Among the ECs tested, AZN, a macrolide antibiotic of significant environmental concern due to its persistence and antimicrobial activity41, exhibited the slowest electron transfer kinetics. At a high frequency of 47 Hz, AZN displayed a weak oxidation signal between 0.5 and 1.0 V (Fig. 3a). However, as the frequency decreased, the oxidation peak increased markedly, suggesting a strong dependence on electron transfer rate42. This trend reflects the sluggish redox kinetics of AZN, which is further corroborated by the monotonic increase of normalized third harmonic current (I3/f) with decreasing frequency. A similar trend was observed for AMX, CBZ, CIP, and TET, indicating that electron transfer limitation is a common bottleneck in the electrochemical oxidation of ECs. These observations collectively suggest that most ECs in wastewater are characterized by inherently slow interfacial electron transfer processes. Meanwhile, their trace concentrations (ppt-ppm) impose significant mass transfer limitations, reducing the flux of reactants to the electrode surface. These two limitations act in concert that the insufficient delivery of ECs exacerbates the already sluggish electron transfer kinetics, resulting in low overall reaction rates. As a result, in conventional electrochemical degradation systems, only a small portion of the input electrical energy contributes directly to pollutant removal, while the majority is dissipated to overcome polarization and maintain the electric double layer. Recognizing the dual constraints imposed by mass and electron transfer, we selected AZN, a typical macrolide antibiotic (ML), as a representative EC due to its environmental relevance and characteristically slow degradation kinetics, which enables a focused investigation of strategies aimed at improving electrocatalytic performance and energy efficiency.

Overcoming the mismatch of electron flow with sluggish electron transfer of ECs
To elucidate the potential of discharging induced degradation of ECs, DEMS was employed to monitor the real-time evolution of gaseous products near the working electrode. As shown in Fig. 4a, the relative intensity of CO2 increased steadily during the potentiostatic “charging” phase (applied for 300 s), indicating active mineralization of AZN under applied potential. Control experiments (Supplementary Fig. 10) confirmed that the origin of the CO2 signal. In the absence of AZN, the CO2 intensity decreased by 96%, verifying that the detected CO2 primarily arose from AZN mineralization rather than background sources. A minor residual CO2 signal was attributed to the decomposition of the Vaseline used for sealing the DEMS cell. Intriguingly, during the subsequent “discharging” phase under open-circuit, the CO2 signal continued to rise transiently despite the cessation of external voltage. This delayed decline (Δt≈30 s) in CO2 intensity implies that the stored charge within the porous electrode or the electrical double layer sustained further mineralization of AZN even in the absence of an applied potential. To further validate this coupling between stored charge and continued degradation, a series of time-dependent experiments were conducted following different durations of the charging phase (Supplementary Fig. 11). In particular, a brief closed-circuit pulse (0 V, 1 s) was introduced after potentiostatic charging to consume the stored charge, and a sharp decrease in CO2 intensity was observed. This confirms that the stored electrical energy in the electrode and interfacial regions could be effectively released to drive continued AZN mineralization during discharging stage.

To demonstrate the compatibility of c-MIP with the charging-discharging operation mode, its capacitive characteristics were thoroughly investigated. Capacitance fitting based on EIS (Supplementary Fig. 12) revealed a film capacitance (Cfilm) of 2701 ± 773 μF and an electrical double layer capacitance (CEDL) of 12.2 ± 1.4 μF. Differential capacitance analysis by cyclic voltammetry attributed most of the increased faradaic capacitance to quinone groups (Supplementary Fig. 13), whereas PBth-BQ contributed minimally to non-faradaic capacitance. The substantial enhancement in total capacitance (Fig. 4b) was attributed to the porous MIP structure, as supported by BET analysis that the specific surface area increased from 3.28 m2/g to 47.25 m2/g, and pore volume also rose markedly (Supplementary Figs. 14 and 15). To further clarify the origin of capacitance enhancement, the total capacitance was deconvoluted into pseudocapacitive and EDL components and correlated with surface area and pore structure (Supplementary Fig. 17). After electropolymerization, the surface area decreased, and CEDL declined due to the coverage of the dense polymer layer, while a distinct pseudocapacitive response emerged from the introduced quinone redox sites. After extracting templates, both the surface area and pore connectivity increased, accompanied by a pronounced rise in CEDL and a moderate increase in Cpseudo. The pore-sized distribution was centered around 2.6 nm, within the mesopore range, consistent with the enhanced ion-accessible channels that promoted double-layer formation. These trends indicated that the enhanced pore accessibility mainly promoted double-layer formation, while the pseudocapacitance was controlled by the density of exposed redox-active sites. Moreover, the adsorption capacity normalized by surface area exhibited a consistent increase, supporting that improved pore connectivity facilitated pollutant enrichment and charge utilization (Supplementary Fig. 17f). Impressively, the MIP(PBth-BQ)@GC electrode delivered superior continuous discharging performance. As shown in Fig. 4c, discharging curves were collected for various electrodes after a 60-s potentiostatic charging step in 0.1 M Na2SO4. The modification of PBth-BQ resulted in a slower decay in voltage, indicative of enhanced charge retention or higher capacitance. Notably, the discharging duration was significantly extended even in low-electrolyte conditions (0.005 M Na2SO4), as shown in Supplementary Fig. 18. Furthermore, kinetic analysis of PBth-BQ yielded a discharging rate constant (k0’) of 0.216 s−1 (Supplementary Fig. 19), supporting its long-lived redox activity. Moreover, this strategy was validated on alternative substrates, that PBth-BQ and MIP(PBth-BQ) also significantly enhanced the discharging behavior of titanium-based electrodes (Fig. 4c), highlighting its general applicability. Thus, the conductive and porous nature of MIP(PBth-BQ)@GC not only promotes selective AZN adsorption but also acts as temporary energy reservoirs for sustained contaminant degradation. This dual role supports a charging-discharging electrocatalytic degradation pathway, whereby more electrons are stored during the charging stage and subsequently released in a sustained manner during discharging, enabling effective degradation of MLs.

Equipped with capacitive c-MIP, we conducted a series of charging-discharging experiments for energy-efficient pollutants removal. As illustrated in Fig. 4e, the electrode adsorbed approximately 50% of AZN within 1 h via selective binding to imprinted cavities. Upon subsequent DC electrolysis at 1.2 V, 98% of AZN was effectively degraded. Surprisingly, a cyclic “charging-discharging” mode, which introduced a 2-min discharging stage after each charging cycle, achieved comparable removal efficiency to the continuous DC mode, despite reducing the total “circuit-on” time by 66.7%, indicating substantial energy savings. By employing denser sampling during the discharge period, we further confirmed that AZN was substantially degraded in the discharging stage itself (Supplementary Fig. 20a). In contrast, a control charging-pulse procedure that disabled the discharging phase (gray line in Fig. 4e and Supplementary Fig. 20) resulted in much lower removal rates, underscoring the critical role of discharging-associated catalysis. The discharging curves remained stable over 80 cycles, with OCP decreasing gradually from 1.2 V to 0.9 V (Fig. 4d). The subtle change of OCP caused by AZN (Supplementary Fig. 21) suggested that the adsorption of ECs had little effect on the discharging processes. The high efficiency of AZN degradation at lower potentials was corroborated by differential pulse voltammetry (DPV, Supplementary Fig. 22), showing superior activity of MIP(PBth-BQ)@GC over bare GC, attributed to both enhanced AZN enrichment by the MIP and efficient direct electron transfer facilitated by Bth-BQ. The degradation activity exhibited negligible decline even as the OCP decreased to 0.9 V, implying the limited electron transfer in electrochemical oxidation of ECs. Further insights from Supplementary Fig. 23 confirmed that AZN oxidation primarily occurred between 0.7 and 1.4 V, aligning with DEMS data (Supplementary Fig. 24), where CO2 evolution initiated at 0.7 V and remained stable between 0.9 and 1.2 V, supporting sustained mineralization of AZN in the discharging phase.

In terms of durability, the electrode retained its electrochemical capacitance over 1000 continuous charging-discharging cycles (Fig. 4f), and maintained structural integrity throughout a 14-day accelerated lifetime test. Detailed capacity retention behavior over 1000 discharging cycles, as well as FTIR, XPS, and SEM analyses before and after extended cycling, are provided in Supplementary Figs. 25 and 26, confirming the long-term stability of the c-MIP electrode. Nyquist plots and fitted parameters (Rct and n, Supplementary Fig. 27b, c) further validated the long-term stability of the c-MIP architecture. To assess the limits of electron utilization, a prolonged discharging protocol, a 19-min discharging period followed a 1-min charging cycle, was employed, in which the OCP declined from 1.2 V to 0.6 V (Fig. 4g). Although the degradation rate constant decreased at lower potentials, the final AZN removal remained high. In 12 full cycles, the terminal discharging potential stabilized, demonstrating consistency in performance. While the charging-discharging electrocatalysis displayed slightly slower kinetics than DC electrolysis, the final removal rate was comparable (Fig. 4h). In contrast, the gray curve (charging-discharging 3#) concentrated all charging periods at the beginning rather than distributing them cyclically, thereby losing the benefit of alternating charge-discharge regulation and resulting in weaker degradation efficiency. The gray controls in Fig. 4e and h, though configured differently, showed the same discharge suppression and similarly reduced performance. These results collectively confirmed that the cyclic distribution of charging and discharging stages was essential for maintaining high removal efficiency. To further verify the effectiveness of this process at the mineralization level, total organic carbon (TOC) and ion chromatography (IC) analyses were performed. TOC and AZN concentrations decreased simultaneously in the initial adsorption stage (Supplementary Fig. 29), confirming rapid enrichment by the c-MIP electrode. During the charging-discharging stage, TOC exhibited a short-term increase that may be attributed to the release of oxidized intermediates into solution, followed by a steady decline as these species were further degraded. After 5 h, 79.0% ± 2.6% of TOC was removed (95% CI: 74.1%–83.9%), and IC analysis confirmed the absence of NO3−, suggesting substantial mineralization of AZN. LC-MS further indicated that key intermediate products of AZN exhibited reduced toxicity (Supplementary Figs. 30 and 31). Strikingly, energy consumption was dramatically lower that DC electrolysis consumed 35.85 ± 0.55 C to degrade 97.6 ± 0.17% of AZN in 5 h, whereas charging-discharging electrocatalysis achieved 96.7 ± 0.01% degradation using only 3.76 ± 0.19 C, or 10.5 ± 0.4% (95% Confidence Interval: 9.4%–11.6%) of the energy required by the DC mode (Fig. 4i and Supplementary Table 3). The substantial energy savings primarily stem from the synergistic contribution of the c-MIP and the charging-discharging operation, where electrical energy is stored temporarily at the charging stages and then released at the discharge stages, emulating reservoir-like energy redistribution. This process effectively reduces energy dissipation that would otherwise be spent on sustaining electrode polarization and maintaining the electric double layer in continuous DC systems.

To further examine the practical applicability of c-MIP coupled with charging-discharging electrocatalysis, the removal of AZN was tested in lower concentrations and in real water samples. C-MIP captured 45.2, 68.5, and 86.7% of AZN in 60 min when the initial concentration were 5 ppm, 1 ppm, and 0.5 ppm, respectively (Supplementary Fig. 32). At lower initial concentrations, c-MIP coupled with charging-discharging electrocatalysis achieved more effective AZN removal, in which selective adsorption demonstrated remarkable capability of selective adsorption for rapidly enriching the target analyte, especially from dilute solutions. In real water samples, the enrichment of AZN by c-MIP was slightly affected, as the removal rate within 60 min decreased from 47.2% in synthetic water to 36.3% and 40.3% in two real water samples (Supplementary Fig. 33a). This decline can be attributed to the interferences from natural organic matters containing hydroxyl groups. The selectivity of c-MIP toward AZN over other three coexisting ECs in real water was also examined, where c-MIP maintained a high selectivity of 75.6%–87.0% (Supplementary Fig. 34). The charging-discharging processes were also influenced in real water, with lower OCP values during discharging process compared with synthetic systems (Supplementary Fig. 34b), which may be attributed to the low conductivity of real matrices. Consequently, the final AZN removal rate after 5 h decreased from 96.7% in synthetic water to 86.2% and 88.5% in real samples, while electricity consumption also dropped from 3.76 ± 0.19 C to 0.39 ± 0.06 C and 0.48 ± 0.01 C, respectively, indicating high energy efficiency.

Furthermore, the c-MIP platform was extended to validate its capability for selectively enriching diverse ECs. For ECs containing hydroxyl groups like TET, a c-MIP was constructed using 3-TBA as the functional monomer, enabling the formation of boronate ester bonds with hydroxyl groups of TET (Supplementary Fig. 35a). The resulting c-MIP exhibited strong selectivity toward TET (Supplementary Fig. 35b), with minimal interference from DCF and SMX. Similarly, for ECs containing carboxyl groups like DCF, 3,4-diaminothiophene (3,4-NH2-Th) was employed as the functional monomer to form amide bonds (Supplementary Fig. 35c). Although its overall efficiency was slightly inferior to the c-MIPs developed for MLs and TET (Supplementary Fig. 35d), these results confirm that amide bond formation is a viable strategy for imprinting carboxyl-containing contaminants. However, targeting amino-group-containing ECs such as SMX proved more challenging. A c-MIP prepared with 3,4-thiophenedicarboxylic acid as the functional monomer was designed to form amide bonds with SMX (Supplementary Fig. 35e), while the resulting polymer failed to effectively distinguish SMX from TET (Supplementary Fig. 35f). This reduced selectivity can be attributed to the slower kinetics of amide bond formation with amino groups, while TET, bearing multiple hydroxyl groups, rapidly formed stable boronate esters, thereby outcompeting SMX and dominating the binding sites. Taken together, these results indicated that the c-MIP strategy can be readily adapted by tailoring template molecules and selecting complementary functional monomers, thereby enabling selective enrichment of ECs containing hydroxyl or carboxyl functional groups.

To address safety concerns in large-scale applications, specifically the instantaneous current surge associated with constant-voltage (CV) charging, a constant-current-constant-voltage (CCCV) protocol was adopted, inspired by battery technologies43. A cut-off potential of 1.65 V was set to avoid oxygen evolution, as determined by LSV analysis (Supplementary Fig. 36). A constant charging current of 0.07 A was identified as optimal, taking ~20 s to reach the cut-off voltage (Supplementary Fig. 37). Compared to the CV-only method, which reached a peak current of 380 mA, the CCCV protocol peaked at a much lower 70 mA (Fig. 4j), reducing surge-related risks while maintaining degradation performance (Supplementary Fig. 38). Leveraging this optimized procedure, we scaled up the system to a 5 L reactor to assess practical feasibility (Fig. 4k). Despite the increased volume, efficient AZN degradation with low energy input was maintained (Supplementary Fig. 40). The slight drop in removal efficiency was primarily attributed to mass transfer limitations stemming from suboptimal mixing. The radar chart displayed in Fig. 4l summarizes the comprehensive advantages of c-MIP and pulsed electrocatalysis across multiple performance indicators. Compared to PBth-BQ-modified electrodes, the c-MIP system demonstrated superior adsorption capacity, selectivity, and energy efficiency. Furthermore, charging-discharging electrocatalysis outperformed the DC mode in terms of cycling stability and power economy. Although pulsed electrocatalysis has been explored in contexts such as CO2 reduction reaction (CO2RR)44–47 and redox-active electrode stability48,49, its application of “charging-discharging” as a strategy for energy-saving electrocatalysis remains largely unexplored. Our work pioneers this approach, demonstrating that the synergistic integration of c-MIP and charging-discharging electrocatalysis can significantly break the binary constraints of mass transport and electron transfer when addressing trace ECs, offering a promising paradigm for sustainable environmental remediation.

Mechanism of the efficient electrocatalytic removal of targeted ECs
To elucidate the underlying mechanism behind the efficient and energy-saving electrocatalytic degradation of MLs, we further examined the mass and electron transfer dynamics of charging-discharging electrocatalysis using c-MIP electrodes. We first evaluated the targeted mass transfer behavior of c-MIP by testing five ECs. Namely, three target MLs, AZN, roxithromycin (ROX), and clarithromycin (CLA), and two common interferences, TET and CBZ. As shown in Fig. 5a, the c-MIP electrode selectively enriched the targeted MLs from the bulk solution, confirming its molecular recognition ability. To further clarify the driving factors enabling dilute contaminants to approach the electrode surface, adsorption experiments of AZN were conducted under different stirring rates (0–1000 rpm) and initial concentrations (0.5–10 ppm). Higher stirring rates significantly accelerated adsorption kinetics (Supplementary Fig. 41), indicating that external mass transfer was important in dilute systems, while the adsorption capacity increased with concentration, confirming the concentration gradient as the primary driving force. These results provided direct evidence supporting the effective enrichment of trace pollutants by c-MIP electrodes, beyond the molecular recognition effect. More importantly, beyond these generic effects, c-MIP provided a unique advantage over conventional adsorption materials. The imprinted sites can form reversible covalent linkages with target molecules, enabling rapid capture and suppressing desorption, thereby shifting the adsorption-desorption equilibrium toward efficient enrichment. To understand the interaction at a molecular level, we performed density functional theory (DFT) calculations to estimate the binding energies between thiopheneboronic acid (TBA) and the three ECs (Fig. 5e). Among them, AZN exhibited the strongest binding affinity with TBA at −5.34 eV, which likely arises from the boric acid-cis-diol interaction, a highly specific covalent interaction. This selectivity was further reinforced by the “lock-and-key recognition” effect inherent to the spatial structure of the MIP matrix50. Although TET and CBZ also formed interactions with TBA, their calculated binding energies were weaker than that of AZN, yet still stronger than non-specific adsorption on graphite (−0.81 eV), possibly due to boric acid-hydroxyl group bonding.

Second, to probe the electrochemical degradation in the charging stage, in-situ DEMS was employed. During LSV, the evolution profiles and LSV currents of MIP(PBth-BQ)@CS and bare CS were compared (Fig. 5b). MIP(PBth-BQ)@CS showed significantly higher current between 0.7 and 1.4 V, correlating with the earlier onset and higher intensity of CO2 generation starting from 0.9 V. In contrast, bare CS only exhibited notable CO2 evolution at 1.4 V, coinciding with the onset of the oxygen evolution reaction. This indicates that MIP(PBth-BQ)@CS not only enabled earlier and more efficient AZN degradation but also suppressed undesirable side reactions. This enhancement can be attributed to the synergistic effect of preconcentration of AZN molecules via the imprinted polymer matrix, and facilitated direct electron transfer enabled by the PBth-BQ conducting layer.

Third, the discharging profiles and corresponding CO2 evolution of both electrodes further illustrated the electrocatalytic advantage of c-MIP in the discharging stage. As shown in Fig. 5c, the OCP of MIP(PBth-BQ)@CS declined more slowly than that of bare CS, correlating with a greater AZN degradation capacity. At potentials ranging from 0.3 to 1.5 V, the CO2 intensity for c-MIP was over five times higher than that of bare CS during both charging and discharging phases, confirming the effective utilization of stored electrical energy for prolonged pollutant oxidation. To further elucidate the electrostatic environment near the electrodes, finite element simulations were conducted. As shown in Fig. 5f, the c-MIP-modified electrode exhibited a stronger and more persistent electric field compared to bare graphite during the discharging phase. This enhancement enabled sustained electrocatalytic oxidation at higher potentials. Additionally, Fig. 5g showed that c-MIP maintained a higher local concentration of SO4 2− anions, which is favorable for charge compensation and ion migration, thereby contributing to its superior OCP retention and electrocatalytic longevity.

A schematic of the proposed mechanism is presented in Fig. 5d, outlining a three-stage process that synergistically regulates both mass and electron flow. The porous, conductive MIP selectively captures ML molecules from the solution through molecular recognition, efficiently preconcentrating them near the electrode surface. Localized enrichment of ECs and enhanced direct electron transfer via PBth-BQ accelerate pollutant oxidation under mild potentials. The high capacitance of the MIP enables electricity storage during charging, which is subsequently released during discharging to drive continued EC degradation. Meanwhile, degradation of ECs regenerates the imprinted cavities for repeated enrichment and oxidation cycles. Together, these results demonstrate that the c-MIP/charging-discharging electrocatalysis platform offers a comprehensive solution for the selective, efficient, and low-energy removal of trace contaminants. By synergistically combining selective enrichment with capacitive discharge-driven electron delivery, this strategy accelerates mass transport and dynamically synchronizes electron flux with reaction kinetics, achieving high-performance degradation that is both scalable and sustainable.

Methods
FTacV measurements
FTacV was performed in a three-electrode system, which consisted of an Ag/AgCl as the reference electrode (in 3 M KCl), a platinum wire as the counter electrode, and the GCE as the working electrode. Bare GCE electrodes were polished with 0.05 μm α-Al2O3 and rinsed with ultrapure water before experiments. Before electrochemical tests, AZN, AMX, CBZ, CIP, and TET were dissolved in 0.1 M Na2SO4 solution, respectively. Using a chi760f workstation (CHI instruments), alternating current voltammetry tests were carried out, in which 256 data points per sine and 65536 data points in total were collected in each test, and the amplitude was set as 0.06 V, with a sensitivity of 10−5 A/V. According to the DPV experiments that have been carried out before, AZN, TET, and AMX were tested at 0~1.2 V, while the CIP and CBZ were tested at 0~1.4 V. For each EC, four tests of 47, 7, 0.977, and 0.19 Hz were carried out.

In-situ DEMS
A state-of-the-art QAS100 DEMS from Linglu Instruments (Shanghai) Co., Ltd., and an Autolab PGSTAT302N (Metrohm, Switzerland) were used to monitor gases and electrochemical signals. A traditional 3-electrode system containing a modified carbon sheet as the working electrode, a Pt wire as the counter electrode, and Ag/AgCl as the reference electrode was applied. The electrolyte consisted of 5 ppm AZN and 0.1 M Na2SO4. An equilibrium of 200 s was performed before electrocatalysis, and the response of 44 amu (CO2) was recorded with PV Mass Spec, and the electrochemical signals were recorded by Nova 2.1.

Preparation of MIP electrodes
A traditional 3-electrode system was applied in electrochemical tests and electro-polymerization, where GCE, graphite carbon plate (GC, 4×2×0.1 cm), or carbon sheet (CS) was used as the working electrode. For the synthesis of MIP(PBth-BQ), 4 mM benzo [1, 2-b; 4, 5-b′] dithiophene-4, 8-dione (Bth-BQ), 2 mM 3, 3′-bithiophene (3, 3′-Bth), 4 mM AZN, 4 mM 3-TBA, and 0.1 M tetrabutylammonium perchlorate were dissolved in acetonitrile. Then cyclic voltammetry was performed with parameters of 0.5–2.3 V vs. non-aqueous Ag+ electrode, 5 cycles, 50 mV/s. For the synthesis of PBth-BQ, 4 mM Bth-BQ was dissolved, and the same CV program was applied.

A pulse procedure was designed to extract templates (AZN) in MIP(PBth-BQ). In a typical run, the potential was set as 1.2 V for 30 s, and then −1.0 V for 30 s. 30 runs were performed in total.

Electrochemical analysis
The discharging test was carried out with a Gamry Interface 1010E in 0.1 M Na2SO4 solution. The MIP(PBth-BQ)@GC, GC, and Ag/AgCl served as the working, counter, and reference electrodes, respectively. An OCP procedure was performed with a stirring of 500 rpm after 1.2 V for 60 s. To test the electrochemical capacity of quinone groups, a CV scan of −1.0–0.2 V at 5 mV/s was performed in a N2-saturated solution containing 0.1 M KCl and 0.1 M PBS. The faradic capacity contributed by quinone groups can be calculated with the following equation:

Cquinone = 1/vA * ∫ iPA dt (1)

Here, C is the capacity of quinone in mC/cm2, iPA is the peak current in A, t is the scanning time in s, A is the surface area in cm2, and the result of the integration is the faradic area.

To test the total capacitance of the electrode, a CV scan of 0–0.5 V at 20 mV/s was performed in a N2-saturated solution containing 0.1 M KCl and 0.1 M PBS. The CV curves were converted into i-t curves, and the capacitance was calculated. The total capacitance was calculated with the following equation:

Ctotal = i / (A * v) (2)

To further deconvolute contribution of pseudocapacitance and EDL capacitance, CV scans of electrodes were performed in a N2-saturated solution containing 0.1 M KCl and 0.1 M PBS at 20, 50, 100, and 200 mV/s, respectively.

i(V) = k1v + k2v1/2 (3)

Here, i(V) is the current at a fixed potential (V), v is the scanning rate in mV/s, k1v is the contribution of pseudocapacitive effects, and k2v1/2 is the contribution of diffusion-controlled insertion. The integrated pseudocapacitive response was derived from the fitted k1 and k2 values across the potential range51.

An accelerated lifetime test (ALT) was carried out by charging at 1.2 V for 60 s and then discharging for 120 s. 1000 cycles were repeated in total. FT-IR characterization was performed a on a Vertex 70v/80v (Bruker, Germany) with reflectance mode. The water contact angle was determined and fitted with a LSA60 (LAUDA Scientific, Germany). Atomic force microscope (AFM) test was performed on a MultiMode 8-HR (Bruker, Germany) with a silicon tip on nitride lever (SNL-10), where Scan mode was ScanAsyst in air. SEM tests were performed on a Quanta 250 FEG (FEI, USA) with the high voltage set at 15 kV.

Electrocatalysis
Four 100 mL quartz reactors were used for electrocatalysis at 303 K and 500 rpm. 0.5 mL of the sample was taken from the reactor and filtered with a 0.22 μm membrane prior to analysis. The solid extraction and LC-MS determination were described in Supplementary Note 4. All reported data are presented as mean ± standard deviation from at least three independent replicate measurements (n ≥ 3). 95% confidence intervals were calculated and provided in the supplementary information.

Theoretical calculations
The interaction energy of the mentioned structures was calculated using the ORCA (version 5.0.4) software package. All the calculations were carried out using RI-B3LYP-D3(BJ) function with def2-TZVP basis set. The counterpoise method was used to correct the Basis Set Superposition Error. The Finite Element simulation was performed with COMSOL Multiphysics software.

Peer review rounds
[{"round": 1, "reviewer_comments": {"reviewer_1": "This manuscript presents a conductive molecularly imprinted polymer (c-MIP) electrode operated in a charging-discharging mode to synergistically regulate mass transport and electron transfer. This proposed new strategy achieves remarkable energy savings and stability, showing a great practical potential for emerging contaminant remediation. This work has been conducted rigorously, and the results are convincing. Overall, this work is of interest and deserves publication after minor revisions.\nBelow are some questions and suggestions to address:\n1. The water contact angle images in Figure 2 indicate successful MIP synthesis, but incorporating electron microscopy images would provide more direct confirmation.\n2. The maximum adsorption capacity (qₘ) and the AZN adsorption isotherm on c-MIP should be provided.\n3. Are radicals like ·OH and other organic radicals involved in this charging-discharging process?\n4. Initial concentration of contaminants and electrolytes should be provided in the figure captions.\n5. Please clarify whether the adsorption of emerging contaminants such as AZN changes the open-circuit potential of the c-MIP electrode.\n6. The fonts in Figures 2-5 are noticeably small and difficult to read. Increasing font size and clarity would significantly improve readability.\n7. The caption of Figure 2b should be revised to show the reduction peak of Fe(CN)63-.\n8. The punctuation and capitalization in citations should be carefully checked, particularly in refs. 15, 21, 28, and 41.", "reviewer_2": "The authors present an integrated electrocatalytic strategy that combines molecularly imprinted enrichment with capacitive charging-discharging to address the dual bottlenecks of mass transport at ultra-low concentrations and slow interfacial electron transfer. The concept is timely and impactful; the reported ~90% energy reduction, if robustly normalized, would represent a clear advance for trace-level water treatment. Evidence is drawn from multiple complementary techniques- DEMS (CO2 evolution), FTacV/EIS (kinetics and transport), simulations (field and ion distributions), and LC-MS quantification. The earlier CO2 onset and higher intensity for c-MIP compared with bare electrodes are convincing. However, I have several major concerns:\n1.Total Organic Carbon (TOC) or Ion Chromatography (IC) data should be provided to quantitatively determine the mineralization extent over time. Coupling this with the DEMS CO2 signal would allow for a more precise carbon mass balance, distinguishing between mere parent compound degradation and true mineralization to CO2.\n2.Identification of Transformation Products: Liquid Chromatography-Mass Spectrometry (LC-MS) analysis should be employed to identify key intermediate products formed during the charging-discharging process with discussion of their persistence or toxicity.\n3.For removal efficiency, energy consumption, EIS/FTacV parameters, and cycling stability, include replicate measurements (n ≥ 3), report mean ± SD, and provide confidence intervals.\n4.Demonstrate performance in real water matrices, or at minimum in synthetic waters containing NOM, Cl-, and HCO3-, comparing enrichment, energy efficiency, and selectivity.\n5.The causal link between EIS/capacitance and pore structure could be strengthened. After template extraction, (cid:1)ct decreases significantly and membrane/EDL capacitance increases, with BET surface area increasing from 3.28 to 47.25 m2·g-1, which aligns with the statement of “more active sites/channels.” However, it is recommended to further deconvolute the capacitance (pseudocapacitance vs. EDL capacitance) and correlate it with pore size distribution in relation to reaction rate/selectivity (e.g., normalized specific surface area or removal rate per unit charge) to reinforce the mechanistic loop.\n6.Beyond stating “>1,000 cycles, >99% efficiency,” provide capacity retention curves and surface analyses (XPS/FTIR/SEM) before and after extended cycling to rule out fouling of imprinted sites.\n7.The data presented in the figures are central to the narrative of the manuscript. However, I noted several issues with the figure legends that need to be carefully addressed to ensure clarity and accuracy.\nIf these concerns are satisfactorily addressed, the manuscript will be suitable for publication.", "reviewer_3": "I co-reviewed this manuscript with one of the reviewers who provided the listed reports. This is part of the Nature Communications initiative to facilitate training in peer review and to provide appropriate recognition for Early Career Researchers who co-review manuscripts.", "reviewer_4": "This work introduced the dual-function conductive molecularly imprinted polymer electrode to strengthen the adsorption of trace pollutants and charging-discharging electrocatalysis, which achieved low-energy removal of trace pollutants. It is an interesting study for the construction of energy-efficient electrocatalytic system. However, there are comments for authors consideration.\n1. There are some mistakes for the error labeling (such as Lines 215-217). The claim that Fig. 2h illustrates \"discharging behavior of titanium-based electrodes\" is inaccurate. Fig. 2h does not reflect the discharging behavior of titanium-based electrodes.\n2. This research focused on the elimination of trace emerging contaminants and AZN was employed as the model pollutants. However, there were little description of the concentration (5 ppm in-situ DEMS). It would be better to added more experiments about the adsorption and degradation of low concentration AZN to highlight the superiority of conductive molecularly imprinted polymer (c-MIP) electrode.\n3. For charging-discharging electrocatalysis in Fig. 4e and 4h, AZN removal efficiency of gray lines was similar, while the experimental conditions were different. Please add the related discussions.\n4. For the specific adsorption via molecularly imprinted polymer, it should be better to explain the differences of adsorption removal rates in parallel experiments (Fig. 4e and 4h in 1h).\n5. Targeted adsorption enrichment is the key feature for MIP, while authors inferred the Langmuir-type mechanism via the characteristics of MIP layer (thin and uniform) and there were no adsorption experiments. Please provide relevant experiments as evidence.\n6. During the process of charging-discharging electrocatalysis, the degradation in discharging period was the main emphasis. In addition to DEMS, it should be added the removal efficiency of AZN during a charging-discharging process, which could reflect the degradation during the discharge process.\n7. The imprinted polymers were used for the selectively absorption of targeted compounds. Could conductive molecularly imprinted polymer work for emerging contaminants other than azithromycin? Please discuss the general application potential of this strategy for emerging contaminants treatment.\n8. The degradation reaction takes place around the surface of electrode. Pollutant diffusion to the electrode surface from the dilute solution is importance for emerging contaminants treatments. What is the key driving factor of dilute emerging contaminants to electrode surface? How to overcome this diffusion barrier in this work? More evidences are needed to discuss this point."}, "author_response": "Response to Reviewers’ Comments\n# Reviewer 1：\nGeneral Comment: This manuscript presents a conductive molecularly imprinted\npolymer (c-MIP) electrode operated in a charging-discharging mode to synergistically\nregulate mass transport and electron transfer. This proposed new strategy achieves\nremarkable energy savings and stability, showing a great practical potential for\nemerging contaminant remediation. This work has been conducted rigorously, and the\nresults are convincing. Overall, this work is of interest and deserves publication after\nminor revisions.\nResponse: Thanks a lot for your comments. According to your suggestions, each of the\ncomments has been responded point by point.\nComment 1: The water contact angle images in Figure 2 indicate successful MIP\nsynthesis, but incorporating electron microscopy images would provide more direct\nconfirmation.\nResponse: Thank you for this suggestion. We supplemented scanning electron\nmicroscopy images to support the successful synthesis of MIP.\nRevision: Supplementary Fig. 1 and its relevant discussion “The electron microscopy\nimages (Supplementary Fig. 1) supported the successful synthesis of c-MIP.” were\nadded in Line 104 of the manuscript.\nSupplementary Fig. 1 Scanning electron microscopy images of bare carbon sheet (a) and\nMIP(PBth-BQ) (b).\nComment 2: The maximum adsorption capacity (qₘ) and the AZN adsorption isotherm\non c-MIP should be provided.\nResponse: Thank you for this insightful comment. We supplemented adsorption\nexperiments and the adsorption isotherm fitted well with the Langmuir isothermal\nmodel (R2=0.99), which indicated a maximum adsorption capacity of 16.35 ±0.12\nμg/cm2.\nRevision: Supplementary Fig. 3 and its relevant discussion “The AZN adsorption\nisotherm on c-MIP (Supplementary Fig. 3) showed a maximum adsorption capacity (qₘ)\nof 16.35 μg/cm2 and demonstrated a Langmuir-type adsorption behavior (R2=0.99),\nwhich indicated a single layer adsorption.” have been added in Line 139 of manuscript.\nSupplementary Fig. 3 Fitting of the AZN adsorption isotherm on c-MIP with Langmuir (red)\nand Freundlich (gray) isothermal model (c =5 ppm, T=303K, stirring rate=500 rpm, n=3).\nAZN\nComment 3: Are radicals like ·OH and other organic radicals involved in this\ncharging-discharging process?\nResponse: Thanks for your question. We supplemented DMPO and TEMP spin-\ntrapping EPR spectra (Supplementary Fig. 28) and they indicated that there were\nno ·OH and other organic radicals involved in the charging-discharging process.\nRevision:\n(1) Supplementary Fig. 28 has been added.\n(2) Reagents and apparatus used for this experiment have been added to\n“Supplementary Note 1: Chemicals and apparatus” of SI: “Acetonitrile, formic acid,\ntetra-n-butylammonium perchlorate (TBAP), 5,5-dimethyl-1-pyrroline N-oxide\n(DMPO), 2,2,6,6-Tetramethylpiperidine (TEMP), and ferrocene (Fc) were purchased\nfrom Shanghai Aladdin Chemical Reagent CO., Ltd (China).” ……“A BioSpin EMX\nPLUS electron paramagnetic resonance spectrometer (Bruker, German) was used for\nidentification of radicals.”\nSupplementary Fig. 28 DMPO (a) and TEMP (b) spin-trapping EPR spectra of the charging-\ndischarging system in the presence of 5 ppm AZN.\nComment 4: Initial concentration of contaminants and electrolytes should be provided\nin the figure captions.\nResponse: Thank you for your kind reminder. Revisions have been made as below.\nRevision:\nFig. 2“… c I-t & E-t curves of the electric pulse procedure that performed best in 0.1\nM Na SO solution … h Comparison of adsorption capacity of PBth-BQ@GC and\n2 4\nMIP(PBth-BQ)@GC for 5 ppm AZN (T=303 K, stirring rate=500 rpm, n=3\nindependent experiments, the individual data points are also plotted as open\ndiamond)”\nFig. 3 “… The electrolyte was 0.1 M Na SO and all tests were repeated for 3 times.\n2 4\nThe shaded region represents for 95% confidence intervals.”\nFig. 4 “a Electrochemical procedure and real-time response of CO and NO of\n2 2\nMIP(PBth-BQ)@CS in 0.1 M Na SO (initial AZN=5 ppm) b I-t curves of 3\n2 4\nelectrodes in 0.1 M KCl and 0.1 M PBSc Open-circuit potential curves of different\nelectrodes after constant potential charging for 60 s at 1.2 V in a solution of 0.1 M\nNa SO . d-i E-t curves (d, g) and removal of AZN (e, h) by DC and pulsed\n2 4\nelectrocatalysis with MIP(PBth-BQ)@GC (initial AZN=5 ppm; electrolyte=0.1 M\nNa SO ; T=303 K; stirring rate=500 rpm; charging-discharging 1#: 1.2 V for 1 min\n2 4\n+ 0 V for 10 s + OCP for 110 s, 80 loops; charging-discharging 2#: 1.2 V for 1 min\n+ OCP for 2 min, 80 loops; charging-discharging 3#: 1.2 V for 12 min + OCP for\n1188 min; charging-discharging 4#: 1.2 V for 1 min + OCP for 19min s, 12 loops;\nn=3 independent experiments) f Open-circuit potential curves in 1000 cycles of\ndischarging in 0.1 M Na SO i Comparison of electricity consumed in DC and\n2 4\ncharging-dishcarging electrocatalytic processes (initial AZN=5 ppm, electrolyte:\n0.1 M Na SO , T=303 K, stirring rate=500 rpm, n=3) j I-t currents of CV and\n2 4\nCCCV charging processes in 0.1 M Na SO k The 5 L reactor for CCCV charging-\n2 4\ndischarging electrocatalysis of ECs (initial AZN=5 ppm, electrolyte=0.1 M\nNa SO , T=303 K, stirring rate=10 rpm, n=3 independent experiments) l Radar\n2 4\nchart comparing the key performance indicators between different electrocatalytic\nstrategies”\nFig 5 “a Adsorption curves of 3 MLs (AZN, ROX and CLA) and 2 interference (TET,\nCBZ) by MIP electrodes (c =c =c =c =c =1 ppm, T=303 K, stirring\nAZN ROX CLA TET CBZ\nrate=500 rpm, n=3 independent experiments) b LSV curves of MIP(PBth-\nBQ)@CS and CS in the presence of 5 ppm AZN and real-time response of CO\n2\nand O in 0.1 M Na SO c CO response of MIP(PBth-BQ)@CS and CS in\n2 2 4 2\ncharging-discharging process (c =5 ppm, electrolyte: 0.1 M Na SO ) …”\nAZN 2 4\nComment 5: Please clarify whether the adsorption of emerging contaminants such as\nAZN changes the open-circuit potential of the c-MIP electrode.\nResponse: Thank you for your constructive advice. To clarify this point, we conducted\nan additional experiment to monitor the contribution of the adsorption of AZN to the\nopen circuit potential (OCP) of the c-MIP. The addition of 50 ppm AZN made subtle\nchange to the OCP of c-MIP (~0.01 V), which is negligible in compare with the OCP\nchanges in the discharging process (~0.6 V). This result indicates that adsorption of\nAZN has little effect on the OCP and does not interfere with the interpretation of\ndischarging-driven catalysis. We have added these results and corresponding discussion\nin the revised manuscript.\nRevision: Supplementary Fig. 21 has been added. An explanation has been added in\nLines 255-257: “The subtle change of OCP caused by AZN (Supplementary Fig. x)\nsuggested that the adsorption of ECs had little effect on the discharging processes”.\nSupplementary Fig. 21 Open circuit potential of the c-MIP electrode with AZN added.\nComment 6: The fonts in Figures 2-5 are noticeably small and difficult to read.\nIncreasing font size and clarity would significantly improve readability.\nResponse:Thanks for pointing out. We have increased the font size of axis labels, tick\nmarks, and legends in Figures 2-5, and optimized the line thickness and contrast to\nimprove overall readability.\nRevision:Figures 2-5 have been updated.\nComment 7: The caption of Figure 2b should be revised to show the reduction peak of\nFe(CN) 3-.\nFigure 2b to explicitly indicate the reduction peak of Fe(CN) 3-, and we double-checked\n6\nall figure captions in the manuscript to avoid similar ambiguities.\nRevision:The caption of Figure 2b has been changed to “The square wave voltammetry\nof MIP(PBth-BQ)@GCE in the solution of 10 mM Fe(CN) 3- before and after\n6\nextracting templates with different electrochemical procedures”.\nComment 8: The punctuation and capitalization in citations should be carefully\nchecked, particularly in refs. 15, 21, 28, and 41.\nResponse: Thank you for catching these errors. We have carefully checked the citations\nand updated.\nRevision:The punctuation and capitalization in Refs. 15, 21, 28, 35, and 41 have been\ncorrected.\n# Reviewer 2：\nGeneral Comment: The authors present an integrated electrocatalytic strategy that\ncombines molecularly imprinted enrichment with capacitive charging-discharging to\naddress the dual bottlenecks of mass transport at ultra-low concentrations and slow\ninterfacial electron transfer. The concept is timely and impactful; the reported ~90%\nenergy reduction, if robustly normalized, would represent a clear advance for trace-\nlevel water treatment. Evidence is drawn from multiple complementary techniques-\nDEMS (CO evolution), FTacV/EIS (kinetics and transport), simulations (field and ion\n2\ndistributions), and LC-MS quantification. The earlier CO onset and higher intensity\n2\nfor c-MIP compared with bare electrodes are convincing.\nResponse: We appreciate your clear and detailed feedback and hope that the\nexplanation has fully addressed all of your concerns. In the remainder of this letter, we\ndiscuss each of your comments individually along with our corresponding responses.\nComment 1: Total Organic Carbon (TOC) or Ion Chromatography (IC) data should\nbe provided to quantitatively determine the mineralization extent over time. Coupling\nthis with the DEMS CO signal would allow for a more precise carbon mass balance,\n2\ndistinguishing between mere parent compound degradation and true mineralization to\nCO .\ncarbon (TOC) and ion chromatography (IC) measurements to quantitatively evaluate\nthe mineralization of AZN. The results (Supplementary Fig. 29) showed that TOC and\nAZN decreased simultaneously in the initial adsorption stage (0-1 h), confirming rapid\nenrichment by the c-MIP electrode. During the subsequent charging-discharging\nprocess (1-5 h), TOC first increased slightly and then decreased, which can be ascribed\nto the rapid oxidation of MIP-enriched AZN into intermediate species that diffused into\nsolution before being further mineralized. After 5 h, 79.0% ± 2.6% of TOC was\nremoved (95% CI: 74.1%-83.9%), and IC analysis confirmed the absence of NO ⁻ (ND,\n3\nc<0.1 mg/L), indicating that most AZN was mineralized. Moreover, LC-MS analysis\nrevealed that the detected intermediates exhibited reduced toxicity. These data have\nbeen incorporated into the revised manuscript.\nRevision: In Lines 288-297, “To further verify the effectiveness of this process at the\nmineralization level, total organic carbon (TOC) and ion chromatography (IC) analyses\nwere performed. TOC and AZN concentrations decreased simultaneously in the initial\nadsorption stage (Supplementary Fig. 29), confirming rapid enrichment by the c-MIP\nelectrode. During the charging-discharging stage, TOC exhibited a short-term increase\nthat may be attributed to the release of oxidized intermediates into solution, followed\nby a steady decline as these species were further degraded. After 5 h, 79.0% ± 2.6% of\nTOC was removed (95% CI: 74.1%-83.9%), and IC analysis confirmed the absence of\nNO -, suggesting substantial mineralization of AZN. LC-MS further indicated that key\n3\nintermediate products of AZN exhibited reduced toxicity (Supplementary Fig. 30-31).”\nhas been added.\nIn Lines 30-32 of SI, “A multi-N/C 3100 TOC analyzer (Analytik Jena AG, Jena,\nGermany) was used to determine total organic carbon, and an ICS-5000 (Thermo Fisher,\nU.S.) was used to determine the NO - of solution” has been added.\nadsorption and charging-discharging process. (5 ppm AZN, 0.1 M Na SO , T=303 K, n=3)\n2 4\nComment 2: Identification of Transformation Products: Liquid Chromatography-Mass\nSpectrometry (LC-MS) analysis should be employed to identify key intermediate\nproducts formed during the charging-discharging process with discussion of their\npersistence or toxicity.\nResponse: Thank you for your constructive advice. The key intermediate products were\nidentified via LC-MS, which revealed that the degradation of azithromycin (AZN)\nduring the charging-discharging process proceeded primarily through pathways\ninvolving ring-opening and cleavage of the desosamine moiety. Notably, predictions\nusing ECOSAR software indicated that these degradation products generally exhibited\nreduced toxicity.\nRevision: In Line 296-297: “LC-MS further indicated that key intermediate products\nof AZN exhibited reduced toxicity (Supplementary Figs. 30-31).” has been added.\nSupplementary Note 5 has been added: “Analysis of degradation products was\nperformed with the same LC parameters. The MS scan adopted MSE mode, with a\nscanning range of 50-800 m/z, a scanning time of 0.2 s, a low collision energy of 6 eV,\nan ion source temperature of 120 °C, a desolvation temperature of 500 °C, a cone gas\nflow of 50 L/h, a desolvation gas flow of 900 L/h, and a capillary voltage of 3 kV. Key\nintermediate products of AZN formed during the charging-discharging process were\nshown in Supplementary Fig. 30.\nThe acute toxicity and chronic toxicity of AZN and its degradation intermediates\ngenerated towards aquatic organisms (fish, daphnid and green algae) was evaluated by\necological structure activity relationship model (ECOSAR) class program VER2.0\nsoftware. The software uses the prediction method based on characteristic groups to\npredict toxicity. When there are multiple groups of toxic groups at the same time, the\nmost toxic group of data can be used. According to the EU standard, acute toxicity\nconcentration > 100 mg/L is harmless; According to Chinese hazardous chemicals\nassessment guidelines (HJ/TI 154-2004), chronic toxicity level > 10 mg/L is harmless.”\nSupplementary Fig. 30 MS scan of key intermediate products of AZN formed during the\ncharging-discharging process\nSupplementary Fig. 31 Acute toxicity (a) and chronic toxicity (b) for AZN and its degradation\nintermediates. Green means harmless, sky blue means harmful, yellow means toxic, and red\nmeans highly toxic. LC50: Lethal Concentration 50; EC50: concentration for 50% of maximal\neffect; ChV: Chronic Value\nComment 3: For removal efficiency, energy consumption, EIS/FTacV parameters, and\ncycling stability, include replicate measurements (n ≥ 3), report mean ± SD, and provide\nconfidence intervals.\nResponse: Thank you for the detailed review. We have revised the manuscript to\ninclude replicate measurements (n ≥ 3) and now reported all key results, including\nremoval efficiency, energy consumption, EIS/FTacV parameters, and cycling stability,\nas mean ± SD. In addition, 95% confidence intervals have been calculated and\nincorporated into the discussion, figures, and Supplementary Tables to strengthen the\nstatistical rigor of the study.\nRevision:\nIn Line 34, “while maintaining 99% (95% Confidence Interval: 98.0% - 100.0%)\nefficiency over 1,000 cycles.” has been added.\nIn Lines 298-301, “Strikingly, energy consumption was dramatically lower that\nDC electrolysis consumed 35.85 ± 0.55 C to degrade 97.6 ± 0.17% of AZN in 5 h,\nwhereas charging-discharging electrocatalysis achieved 96.7 ± 0.01% degradation\nusing only 3.76 ± 0.19 C, or 10.5 ± 0.4% (95% Confidence Interval: 9.4% - 11.6%) of\nthe energy required by the DC mode (Fig. 4i and Supplementary Table 3).”\nIn Lines 535-537, “All reported data are presented as mean ± standard deviation\nfrom at least three independent replicate measurements (n ≥ 3). 95% confidence\nintervals were calculated and provided in the supplementary information.” has been\nadded.\nFigure 3, Supplementary Figures 4-9, Supplementary Tables 1, 3 have been\nupdated, and Supplementary Tables 5-6 have been added.\nFig. 3 | Kinetic behaviors of typical ECs revealed by FTacV\na The 3rdharmonic components extracted fromFTacV measurements of bare GCE in the presence\nof AZN (red) and in the absence of AZN (black) at multiple frequencies: 47, 7, 0.977, 0.19 Hz. b-e\n3rd harmonic ACV of CBZ, AMX, CIP, and TET. The electrolyte was 0.1 M Na SO and all tests\n2 4\nwere repeated for 3 times. The shaded region represents for 95% confidence intervals.\nSupplementary Table 1 | EIS fitting results of electrodes at different stages\n95% Confidence After extraction 95% Confidence 95% Confidence\nParameters Before extraction After ALT of 14 d\nInterval (Before ALT) Interval Interval\nR (Ω) 20.2 ±0.1 20.0 – 20.5 23.6 ±3.3 15.4 – 31.8 24.2 ±6.6 8.0 – 40.5\nsol\nR (Ω) 4358.0 ±98.8 4112.5 – 4603.5 60.9 ±7.0 43.6 – 78.2 56.0 ±3.0 48.7 – 63.3\nct\nC (μF) 8.7 ±0.03 7.9 – 9.6 12.2 ±1.4 9.7 – 15.7 24.1 ±5.6 26.6 – 28.0\nEDL\nC (μF) 24.9 ±2.1 19.8 – 30.0 2701.3 ±772.9 781.2 – 4621.4 2457.5 ± 178.9 2098.3 – 2765.0\nfilm\nn 0.92 ±0.01 0.89 – 0.95 0.63 ±0.02 0.57 – 0.68 0.68 ±0.03 0.60 – 0.75\nr2 >0.999 >0.999 >0.999 >0.999 >0.999 >0.999\nAll EIS parameters are reported as mean ± SD, n=3 independent experiments.\nSupplementary Table 3 | Electricity consumed by charging-discharging and DC electrocatalysis\nElectricity of charging-discharging electrocatalysis(C) Electricity of DC electrocatalysis(C)\nRuns\n1# 2# 3# 1# 2# 3#\n1 0.4632 0.4871 0.6509\n2 0.4289 0.3476 0.4106\n3 0.3739 0.3105 0.3397\n4 0.3434 0.291 0.3068\n5 0.3272 0.2823 0.2858\n6 0.3128 0.2748 0.2744\n7 0.3034 0.2662 0.2656\n8 0.2947 0.2598 0.2557\n9 0.2917 0.2551 0.2502\n10 0.2856 0.251 0.2474\n11 0.2811 0.2478 0.2422\n12 0.2759 0.2449 0.2375\nTotal 3.9818 3.5181 3.7668 36.60 35.67 35.29\nMean 3.76 ± 0.19 (95% CI: 3.28 – 4.23) 35.85 ± 0.55 (95% CI: 34.49 – 37.22)\nSupplementary Table 5 | Electricity consumed by charging-discharging electrocatalysis in real water samples\nElectricity consumed in real water 1(C) Electricity consumed in real water 2(C)\nRuns\n1# 2# 3# 1# 2# 3#\n1 0.0509 0.0545 0.0241 0.0444 0.0319 0.0503\n2 0.0411 0.0424 0.0256 0.0426 0.0453 0.0460\n3 0.0383 0.0386 0.0254 0.0426 0.0428 0.0435\n4 0.0364 0.0364 0.0255 0.0419 0.0410 0.0420\n5 0.0353 0.0349 0.0256 0.0401 0.0397 0.0408\n6 0.0344 0.0338 0.0255 0.0398 0.0387 0.0399\n7 0.0337 0.0331 0.0253 0.0394 0.0380 0.0392\n8 0.0332 0.0324 0.0251 0.0378 0.0374 0.0386\n9 0.0325 0.0319 0.0249 0.0379 0.0369 0.0382\n10 0.0320 0.0315 0.0247 0.0369 0.0365 0.0378\n11 0.0316 0.0310 0.0245 0.0369 0.0361 0.0375\n12 0.0312 0.0308 0.0243 0.0365 0.0358 0.0372\nTotal 0.4307 0.4313 0.3005 0.4766 0.4601 0.4911\nMean 0.39 ± 0.06 (95% CI: 0.23 – 0.54) 0.48 ± 0.01 (95% CI: 0.44 – 0.51)\nSupplementary Table 6 | Data of AZN removal and 95% confidence interval\nGroup t(min) C/C SD 95% CI- 95% CI+\nt 0\n0 100.0% 0.0% 100.0% 100.0%\n10 69.4% 4.1% 65.0% 73.7%\n20 63.1% 2.6% 60.3% 65.9%\n40 57.7% 2.2% 55.4% 60.4%\n1.2 V, DC\n60 52.8% 4.5% 48.1% 57.4%\n120 22.4% 0.5% 21.1% 23.6%\n180 9.5% 1.7% 5.3% 13.7%\n300 2.4% 1.7% -1.9% 6.8%\n0 100.0% 0.0% 100.0% 100.0%\n10 69.4% 4.1% 65.0% 73.7%\n20 63.1% 2.6% 60.3% 65.9%\n40 57.7% 2.2% 55.4% 60.4%\nCharging-discharging 1#\n60 52.8% 4.5% 48.1% 57.4%\n120 37.4% 2.0% 32.4% 42.3%\n180 31.1% 0.9% 28.9% 33.2%\n300 28.7% 1.8% 24.1% 33.3%\n0 100.0% 0.0% 100.0% 100.0%\n10 69.4% 4.1% 65.0% 73.7%\n20 63.1% 2.6% 60.3% 65.9%\n40 57.7% 2.2% 55.4% 60.4%\nCharging-discharging 2#\n60 52.8% 4.5% 48.1% 57.4%\n120 20.2% 1.8% 15.7% 24.7%\n180 7.3% 1.1% 4.5% 10.0%\n300 1.1% 0.3% 0.5% 1.8%\n0 100.0% 0.0% 100.0% 100.0%\n10 69.4% 4.1% 65.0% 73.7%\n20 63.1% 2.6% 60.3% 65.9%\nCharging-discharging 3# 40 57.7% 2.2% 55.4% 60.4%\n60 52.8% 4.5% 48.1% 57.4%\n120 34.8% 1.6% 30.8% 38.9%\n300 33.8% 2.0% 28.9% 38.7%\n0 100.0% 0.0% 100.0% 100.0%\n10 69.4% 4.1% 65.0% 73.7%\n20 63.1% 2.6% 60.3% 65.9%\n40 57.7% 2.2% 55.4% 60.4%\nCharging-discharging 4#\n60 52.8% 4.5% 48.1% 57.4%\n120 30.8% 2.7% 24.0% 37.6%\n180 15.7% 1.5% 11.9% 19.4%\n300 3.3% 0.1% 3.1% 3.4%\nComment 4: Demonstrate performance in real water matrices, or at minimum in\nsynthetic waters containing NOM, Cl-, and HCO -,\n3\ncomparing enrichment, energy efficiency, and selectivity.\nResponse: Thank you for your constructive comments. In response, we conducted\nadditional tests in real wastewater samples that inherently contain NOM, inorganic\nanions, and other background constituents. The results (Lines 316-329, Supplementary\nFigs. 33-34) showed that although the enrichment efficiency of c-MIP toward AZN\ndecreased slightly compared with synthetic water, the polymer still maintained high\nselectivity (75.6-87.0%) and robust degradation performance. Moreover, the charging-\ndischarging mode in real water consumed significantly less electricity while still\nachieving >86% removal after 5 h. These results confirmed that the c-MIP strategy was\ntolerant to complex water matrices and retained good applicability in realistic scenarios.\nRevision: In Line 316-328, “In real water samples, the enrichment of AZN by c-MIP\nwas slightly affected, as the removal rate within 60 min decreased from 47.2% in\nsynthetic water to 36.3% and 40.3% in two real water samples (Supplementary Fig.\n33a). This decline can be attributed to the interferences from natural organic matters\n(NOMs) that containing hydroxyl groups. The selective of c-MIP toward AZN over\nother three coexisting ECs in real water was also examined, where c-MIP maintained a\nhigh selectivity of 75.6%-87.0% (Supplementary Fig. 34). The charging-discharging\nprocesses were also influenced in real water, with lower OCP values during discharging\nprocess compared with synthetic systems (Supplementary Fig. 34b), which may be\nattributed to the low conductivity of real matrices. Consequently, the final AZN removal\nrate after 5 h decreased from 96.7% in synthetic water to 86.2% and 88.5% in real\nsamples, while electricity consumption also dropped from 3.76 ± 0.19 mC to 0.39 ±\n0.06 mC and 0.48 ± 0.01 mC, respectively.” has been added, with 95% confidence\nintervals reported in Supplementary Table 5.\nDetails of collection of water samples and the verification experiment were added\nin SI: “Effluents of wastewater treatment plants (WWTPs) in Jiangsu and Guangdong\nprovince were collected at spring of 2025, filtered through 0.22 μm membranes to\nexclude microorganisms, and stored at -20 ℃. Information of two WWTPs and basic\nindicators of these 2 samples were listed in Supplementary Table 4. 5 ppm AZN was\nadded prior to the adsorption and charging-discharging experiments, and no extra\nelectrolyte was supplemented. For selectivity tests in real water samples, 1 ppm AZN,\n1 ppm SMX, 1 ppm CBZ and 1 ppm DCF were added prior to adsorption experiments.”\nSupplementary Fig. 33 a Removal of 5 ppm AZN in real wastewater samples by charging-\ndischarging electrocatalysis with c-MIP electrodes (T=303 K, stirring rate=500 rpm,\nelectrolyte=0.1 M Na SO , charging=1 min, discharging=19 min， n=3) b Charging potential\n2 4\nand open circuit potential of c-MIP during discharging processes in 2 real wastewater samples.\nSupplementary Fig. 34 Adsorption amounts and selectivity of c-MIP towards 1 ppm AZN over\n3 inferences (1 ppm SMX, 1 ppm CBZ, and 1 ppm DCF) in real wastewater sample. (T=303 K,\nstirring rate=500 rpm, n=3)\nSupplementary Table 4. Information of 2 WWTPs and basic indicators of their effluents\nCapacity Treatment TOC TN Conductivity\nProvince pH\n(×103 t/d) processes (mg/L) (mg/L) (μS/cm)\nJiangsu 80 AAO 6.27 ±0.06 10.70 ±0.16 8.31 662.2 ±0.4\nGuangdong 300 AAO+MBR 4.61 ±0.05 7.41 ±0.09 7.40 385.8 ±0.4\nComment 5: The causal link between EIS/capacitance and pore structure could be\nstrengthened. After template extraction, ct decreases significantly and membrane/EDL\ncapacitance increases, with BET surface area increasing from 3.28 to 47.25 m2·g-1,\nwhich aligns with the statement of “more active sites/channels.” However, it is\nrecommended to further deconvolute the capacitance (pseudocapacitance vs. EDL\ncapacitance) and correlate it with pore size distribution in relation to reaction\nrate/selectivity (e.g., normalized specific surface area or removal rate per unit charge)\nto reinforce the mechanistic loop.\nResponse: We appreciate your valuable suggestions. In response, we deconvoluted the\ntotal capacitance into pseudocapacitive and electrical double-layer (EDL) components,\nand correlated these findings with specific surface area and pore structure, all presented\nin Supplementary Fig. 17. For clarity, the description of the capacitance measurement\nin the Methods section was refined to “total capacitance”, consistent with the\nsubsequent separation of pseudo and EDL contributions.\nAfter the electropolymerization of MIP on GC electrodes, the surface area\ndecreased from 30.09 to 3.28 m2/g, indicating coverage by a dense polymer layer.\nCorrespondingly, C declined from 0.85 to 0.26 mC/cm2 (Supplementary Fig. 17d)\nEDL\nas ion-accessible surface decreased, while a distinct pseudocapacitive response\nemerged owing to the introduction of quinone-based redox sites within the polymer\nnetwork. Following template extraction, the surface area increased significantly to\n47.25 m2/g, and the most probable pore size expanded slightly from 2.46 to 2.61 nm,\nindicating the opening and interconnection of imprinted cavities within the mesopore\nrange (2-3 nm). These structural changes led to a pronounced rise in C (\nEDL\nfrom 0.26 to 2.57 mC/cm2) and a moderate increase in C (from 3.09 to 4.78\npseudo\nmC/cm2). The parallel increase in C and accessible surface area confirmed that the\nEDL\nenlarged pore channels promoted electrolyte penetration and double-layer formation,\nwhile the limited variation in C indicated that the faradaic contribution was\npseudo\nprimarily determined by the number of exposed redox-active sites rather than by the\ntotal area.\nC increased almost proportionally with surface area, indicating that the\nEDL\nenlargement of accessible pores and improved electrolyte penetration were primarily\nresponsible for the development of the double-layer region (Supplementary Fig. 17e).\nIn contrast, C exhibited only a weak dependence on surface area, suggesting that\npseudo\nthe faradaic process was mainly controlled by the number of exposed redox-active sites\nrather than by total geometric area. The adsorption capacity normalized by surface area\nfollowed the same increasing trend among the three electrodes, implying that improved\npore accessibility facilitated pollutant enrichment and enhanced charge utilization\n(Supplementary Fig. 17f). These results collectively reinforced the mechanistic\nrelationship among pore architecture, capacitive behavior, and reaction performance.\nRevision:In Lines 211-225, “To further clarify the origin of capacitance enhancement,\nthe total capacitance was deconvoluted into pseudocapacitive and EDL components and\ncorrelated with surface area and pore structure (Supplementary Fig. 17). After\nelectropolymerization, the surface area decreased and C declined due to the\nEDL\ncoverage of the dense polymer layer, while a distinct pseudocapacitive response\nemerged from the introduced quinone redox sites. After extracting templates, both the\nsurface area and pore connectivity increased, accompanied by a pronounced rise in C\nEDL\nand a moderate increase in C . The pore-size distribution was centered around 2.6\npseudo\nnm, within the mesopore range, consistent with the enhanced ion-accessible channels\nthat promoted double-layer formation. These trends indicated that the enhanced pore\naccessibility mainly promoted double-layer formation, while the pseudocapacitance\nwas controlled by the density of exposed redox-active sites. Moreover, the adsorption\ncapacity normalized by surface area exhibited a consistent increase, supporting that\nimproved pore connectivity facilitated pollutant enrichment and charge utilization\n(Supplementary Fig. 17f).” has been added.\nSupplementary Fig. 17 has been added.\nIn Lines 521-527, methods for quantifying the contribution of pseudocapacitance\nand EDL capacitance has been added: “To further deconvolute contribution of\npesudocapacitance and EDL capacitance, CV scans of electrodes were performed in a\nN -saturated solution containing 0.1 M KCl and 0.1 M PBS at 20, 50, 100, 200 mV/s,\n2\nrespectively.\n(3)\n1/2\nHere, i(V) is the current at a\n𝑖(\nf\n𝑉\nix\n)\ne\n=\nd p\n𝑘\no1te\n𝑣\nnt\n+\nia\n𝑘\n1(2V\n𝑣\n), v is the scanning rate in mV/s, k\n1\nv\nis the contribution of pseudocapacitive effects, and k v is the contribution of diffusion-\n2\ncontrolled insertion. The integrated pseudocapacitive response was derived from the\nfitted k and k values across the potential range51”.\n1 2\nIn Line 517, “To test the non-faradic capacitance of the electrode” has been\nchanged to “To test the total capacitance of the electrode”, and equation (2) has been\nchanged to:\n(2)\n𝑖𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑎𝑛𝑐𝑒\n𝐶𝑡𝑜𝑡𝑎𝑙 =\n𝐴𝑣\nReference:\n51. Brezesinski T, Wang J, Tolbert SH, Dunn B. Ordered mesoporous α-MoO with\n3\niso-oriented nanocrystalline walls for thin-film pseudocapacitors. Nat. Mater. 9,\n146-151 (2010).\nSupplementary Fig. 17 | a-c Pseudocapacitive contributions to the total current for bare GC(a),\nMIP before extraction (b), and MIP after extraction (c) d Deconvoluted pseudocapacitance,\nEDL capacitance, and most probable pore size (mode) of bare GC and MIP before and after\nextracting AZN e Comparison of pseudocapacitance and EDL capacitance of bare GC and MIP\nbefore and after extracting AZN as a function of specific surface area. f Specific adsorption of\nAZN normalized to BET area for bare GC and MIPs in 10 min. (c =5 ppm, T=303K, n=3)\nretention curves and surface analyses (XPS/FTIR/SEM) before and after extended\ncycling to rule out fouling of imprinted sites.\nResponse: Thank you for this valuable comment. To address it, we have added capacity\nretention curves and surface analyses. Specifically, the potential values at fixed\ndischarging times (0, 0.5, 1, and 2 min) were monitored over 1000 discharging cycles\nand used as indicators of charge retention, thereby representing the capacity retention\nbehavior of the c-MIP electrode (Supplementary Fig. 25). The results showed negligible\ndecay, confirming excellent electrochemical stability. In addition, FTIR and XPS\ncharacterizations before and after 1000 cycles (Supplementary Fig. 26) demonstrated\nthat the characteristic functional groups of imprinted sites were preserved, ruling out\nfouling or collapse of the MIP framework. The SEM images showed continuous c-MIP\nlayers without cracking, while the slightly denser surface texture after cycling was\nattributable to superficial residues rather than structural deterioration. These results\nhave been added and discussed in the revised manuscript.\nRevision: In Lines 269-272, “Detailed capacity retention behavior over 1000\ndischarging cycles, as well as FTIR, XPS, and SEM analyses before and after extended\ncycling, are provided in Supplementary Figs. 25-26, confirming the long-term stability\nof the c-MIP electrode.” has been added.\nSupplementary Fig. 25 a Discharging curves of the c-MIP in 1000 “charging-discharging”\ncycles and b capacity retention curves of the c-MIP at 0 min, 0.5 min, 1 min, and 2 min of each\ndischarging processes.\nSupplementary Fig. 26 a FT-IR spectrum, b O1s XPS spectrum, and SEM images of c-MIP\nbefore (c) and after 1000 cycles of stability tests (d)\nComment 7: The data presented in the figures are central to the narrative of the\nmanuscript. However, I noted several issues with the figure legends that need to be\ncarefully addressed to ensure clarity and accuracy.\nResponse: Thank you for this important comment. We carefully checked all figure\nlegends and made the necessary corrections to improve clarity and accuracy.\nSpecifically, the mistaken reference to “Fig. 2h” has been corrected to “Fig. 4c,” and\nthe plot legends in Fig. 4e and 4h have been revised. In addition, the figure legends of\nFigs. 2-5 have been expanded and standardized to provide full descriptions of the\nexperimental conditions and parameters. These revisions ensure that the figures can be\nunderstood independently and that the legends accurately reflect the data presented.\nRevision:\n“Fig. 2h” in Line 236 has been changed to “Fig. 4c”.\nPlot legends of Fig.4e and h have been updated.\nFig. 2“a Schematic of preparation of MIP(PBth-BQ)@GC. b The square wave\nvoltammetry of MIP(PBth-BQ)@GCE in the solution of 10 mM Fe(CN) 3- before\n6\nand after extracting templates with different electrochemical procedures. c I-t &\nE-t curves of the electric pulse procedure that performed best in 0.1 M Na SO\n2 4\nsolution … h Comparison of adsorption capacity of PBth-BQ@GC and\nMIP(PBth-BQ)@GC for 5 ppm AZN (T=303 K, stirring rate=500 rpm, n=3\nindependent experiments, the individual data points are also plotted as open\ndiamond)”\nFig. 3 “… The electrolyte was 0.1 M Na2SO4 and all tests were repeated for 3 times.\nThe shaded region represents for 95% confidence intervals.”\nFig. 4 “a Electrochemical procedure and real-time response of CO and NO of\n2 2\nMIP(PBth-BQ)@CS in 0.1 M Na SO (initial AZN=5 ppm) b I-t curves of 3\n2 4\nelectrodes in 0.1 M KCl and 0.1 M PBSc Open-circuit potential curves of different\nelectrodes after constant potential charging for 60 s at 1.2 V in a solution of 0.1 M\nNa SO . d-i E-t curves (d, g) and removal of AZN (e, h) by DC and pulsed\n2 4\nelectrocatalysis with MIP(PBth-BQ)@GC (initial AZN=5 ppm; electrolyte=0.1 M\nNa SO ; T=303 K; stirring rate=500 rpm; charging-discharging 1#: 1.2 V for 1 min\n2 4\n+ 0 V for 10 s + OCP for 110 s, 80 loops; charging-discharging 2#: 1.2 V for 1 min\n+ OCP for 2 min, 80 loops; charging-discharging 3#: 1.2 V for 12 min + OCP for\n1188 min; charging-discharging 4#: 1.2 V for 1 min + OCP for 19min s, 12 loops;\nn=3 independent experiments) f Open-circuit potential curves in 1000 cycles of\ndischarging in 0.1 M Na SO i Comparison of electricity consumed in DC and\n2 4\ncharging-dishcarging electrocatalytic processes (initial AZN=5 ppm, electrolyte:\n0.1 M Na SO , T=303 K, stirring rate=500 rpm, n=3) j I-t currents of CV and\n2 4\nCCCV charging processes in 0.1 M Na SO k The 5 L reactor for CCCV charging-\n2 4\ndischarging electrocatalysis of ECs (initial AZN=5 ppm, electrolyte=0.1 M\nNa SO , T=303 K, stirring rate=10 rpm, n=3 independent experiments) l Radar\n2 4\nchart comparing the key performance indicators between different electrocatalytic\nstrategies”\nFig 5 “a Adsorption curves of 3 MLs (AZN, ROX and CLA) and 2 interference (TET,\nCBZ) by MIP electrodes (c =c =c =c =c =1 ppm, T=303 K, stirring\nAZN ROX CLA TET CBZ\nrate=500 rpm, n=3 independent experiments) b LSV curves of MIP(PBth-\nBQ)@CS and CS in the presence of 5 ppm AZN and real-time response of CO\n2\nand O in 0.1 M Na SO c CO response of MIP(PBth-BQ)@CS and CS in\n2 2 4 2\ncharging-discharging process (c =5 ppm, electrolyte: 0.1 M Na SO ) …”\nAZN 2 4\n# Reviewer 3：\nGeneral Comment: I co-reviewed this manuscript with one of the reviewers who\nprovided the listed reports. This is part of the Nature Communications initiative to\nfacilitate training in peer review and to provide appropriate recognition for Early\nCareer Researchers who co-review manuscripts.\nResponse: Thank you very much for your time involved in reviewing the manuscript\nand your very encouraging comments on the merits.\n# Reviewer 4：\nGeneral Comment: This work introduced the dual-function conductive molecularly\nimprinted polymer electrode to strengthen the adsorption of trace pollutants and\ncharging-discharging electrocatalysis, which achieved low-energy removal of trace\npollutants. It is an interesting study for the construction of energy-efficient\nelectrocatalytic system. However, there are comments for authors consideration.\nResponse: Thank you for your comments. We have implemented corrections according\nto the reviewer’s comments and details of the specific revisions are outlined below.\nComment 1: There are some mistakes for the error labeling (such as Lines 215-217).\nThe claim that Fig. 2h illustrates \"discharging behavior of titanium-based electrodes\"\nis inaccurate. Fig. 2h does not reflect the discharging behavior of titanium-based\nelectrodes.\nResponse: Thank you for pointing out this error. The reference to “Fig. 2h” in Lines\n215-217 was incorrect; it should have been “Fig. 4c”. We have corrected this in the\nrevised manuscript, and this change does not affect the results or conclusions.\nRevision: “Fig. 2h” in Line 236 has been changed to “Fig. 4c”.\nComment 2: This research focused on the elimination of trace emerging contaminants\nand AZN was employed as the model pollutants. However, there were little description\nof the concentration (5 ppm in-situ DEMS). It would be better to added more\nexperiments about the adsorption and degradation of low concentration AZN to\nhighlight the superiority of conductive molecularly imprinted polymer (c-MIP)\nelectrode.\nResponse: Thank you for your valuable advice. To address this point, we conducted\nadditional experiments on the adsorption and degradation of AZN at low concentrations\n(0.5-5 ppm). The results (Lines 309-316, Supplementary Fig. 32) showed that c-MIP\nelectrodes achieved rapid enrichment and efficient removal even under dilute\nconditions, thereby highlighting their superiority in practical scenarios.\nRevision: In Lines 309-316, “To further examine the practical applicability of c-MIP\ncoupled with charging-discharging electrocatalysis, the removal of AZN was tested in\nlower concentrations and in real water samples. C-MIP captured 45.2%, 68.5%, and\n86.7% of AZN in 60 min when the initial concentration were 5 ppm, 1 ppm, and 0.5\nppm, respectively (Supplementary Fig. 32). At lower initial concentrations, c-MIP\ncoupled with charging-discharging electrocatalysis achieved more effective AZN\nremoval, in which selective adsorption demonstrated remarkable capability of selective\nadsorption for rapidly enriching the target analyte, especially from dilute solutions.”\nhas been added.\nSupplementary Fig. 32 Removal of different concentration of AZN by charging-discharging\nelectrocatalysis with c-MIP (T=303 K, stirring rate=500 rpm, electrolyte=0.1 M Na SO ,\n2 4\ncharging=1 min, discharging=19 min, n=3)\nComment 3: For charging-discharging electrocatalysis in Fig. 4e and 4h, AZN\nremoval efficiency of gray lines was similar, while the experimental conditions were\ndifferent. Please add the related discussions.\nResponse: We thank the reviewer for the inquiry. The gray lines in Fig. 4e (charging-\ndischarging 1#) and Fig. 4h (charging-discharging 3#) represent simplified control\nprotocols. In charging-discharging 1#, a short 0 V pulse immediately after charging\ndisabled the subsequent slow discharging stage, so the removal was mainly contributed\nby the charging periods, leading to lower efficiency. In charging-discharging 3#, the\ntotal charging time was concentrated at the beginning rather than being distributed\ncyclically, which failed to mitigate the mismatch between electron release and the\nsluggish electron transfer of AZN, thereby weakening the degradation performance.\nAlthough the experimental designs were different, both protocols suppressed the\ncontribution of the discharging phase, which explains why their overall AZN removal\nefficiencies appeared similar. We have added clarifications in the revised text.\nRevision: In Lines 281-288, discussion about the gray line of charging-discharging 1#\nand 3# has also been supplemented: “In contrast, the gray curve (charging-discharging\n3#) concentrated all charging periods at the beginning rather than distributing them\ncyclically, thereby losing the benefit of alternating charge-discharge regulation and\nresulting in weaker degradation efficiency. These results collectively confirm that the\ncyclic distribution of charging and discharging stages was essential for maintaining\nhigh removal efficiency. The gray controls in Fig. 4e and 4h, though configured\ndifferently, showed the same discharge suppression and similarly reduced performance.”\nComment 4: For the specific adsorption via molecularly imprinted polymer, it should\nbe better to explain the differences of adsorption removal rates in parallel experiments\n(Fig. 4e and 4h in 1h).\nResponse: Thank you for pointing out this issue. We carefully re-checked the original\ndata for the 1 h adsorption removal, which gave an average c /c of 51.44% ± 5.76%.\n1h 0\nWe noted the slightly larger deviation, which may have arisen from minor uncertainties\nduring sample pretreatment, including dilution and subsequent solid-phase extraction,\nwhere 40 μL of sample was diluted to 3 mL prior to SPE.\nTo further verify data reliability, three additional independent replicates were\nconducted using an isotopically labeled internal standard (AZN-d3) spiked before\nsample preparation rather than after dilution. The additional replicates were statistically\nconsistent with the original data and were combined for integrated reporting. The\ncalculated mean and 95% confidence intervals (Table R1) further confirmed that the\nobserved variation at 1 h fell within the typical uncertainty range of adsorption\nmeasurements.\nTable R1. Removal of AZN by c-MIP adsorption\nt(min) C/C SD 95% Confidence interval\nt 0\n0 100.0% 0.0% 100.0%\n10 69.4% 4.1% 65.0% - 73.7%\n20 63.1% 2.6% 60.3% - 65.9%\n40 57.7% 2.2% 55.4% - 60.4%\n60 52.8% 4.5% 48.1% - 57.4%\nRevision: Fig. 4 has been updated as below.\na Electrochemical procedure and real-time response of CO and NO of MIP(PBth-BQ)@CS in 0.1\n2 2\nM Na SO (initial AZN=5 ppm) b I-t curves of 3 electrodes in 0.1 M KCl and 0.1 M PBS c Open-\n2 4\ncircuit potential curves of different electrodes after constant potential charging for 60 s at 1.2 V in\na solution of 0.1 M Na SO . d-iE-t curves (d, g) and removal of AZN (e, h) by DC and charging-\n2 4\ndischarging electrocatalysis with MIP(PBth-BQ)@GC (initial AZN=5 ppm; electrolyte=0.1 M\nNa SO ; T=303 K; stirring rate=500 rpm; charging-discharging 1#: 1.2 V for 1 min + 0 V for 10 s\n2 4\n+ OCP for 110 s, 80 loops; charging-discharging 2#: 1.2 V for 1 min + OCP for 2 min, 80 loops;\ncharging-discharging 3#: 1.2 V for 12 min + OCP for 1188 min; charging-discharging 4#: 1.2 V for\n1 min + OCP for 19min s, 12 loops; n=3 independent experiments) f Open-circuit potential curves\nin 1000 cycles of discharging in 0.1 M Na SO i Comparison of electricity consumed in DC and\n2 4\ncharging-dishcarging electrocatalytic processes (initial AZN=5 ppm, electrolyte: 0.1 M Na SO ,\n2 4\nT=303 K, stirring rate=500 rpm, n=3 independent experiments) j I-t currents of CV and CCCV\ncharging processes in 0.1 M Na SO k The 5 L reactor for CCCV charging-discharging\n2 4\nelectrocatalysis of ECs (initial AZN=5 ppm, electrolyte=0.1 M Na SO , T=303 K, stirring rate=10\n2 4\nrpm, n=3 independent experiments) l Radar chart comparing the key performance indicators\nbetween different electrocatalytic strategies\nComment 5: Targeted adsorption enrichment is the key feature for MIP, while authors\ninferred the Langmuir-type mechanism via the characteristics of MIP layer (thin and\nuniform) and there were no adsorption experiments. Please provide relevant\nexperiments as evidence.\nResponse: Thank you for your valuable comments. To address it, we conducted\nadsorption isotherm experiments of c-MIP toward AZN. The results (Supplementary\nFig. 3) showed a maximum adsorption capacity (q ) of 16.35 μg/cm2, and the isotherm\nm\nfitted well with the Langmuir model (R2 = 0.99), confirming a monolayer adsorption\nbehavior. The corresponding results and discussion have been added in the revised\nmanuscript.\nRevision:In Lines 139-142, “The AZN adsorption isotherm on c-MIP (Supplementary\nFig. 3) showed a maximum adsorption capacity (qₘ) of 16.35 μg/cm2 and demonstrated\na Langmuir-type adsorption behavior (R2=0.99), which indicated a single layer\nadsorption.” has been added.\nSupplementary Fig. 3 has been added.\nSupplementary Fig. 3 Fitting of the AZN adsorption isotherm on c-MIP with Langmuir (red)\nand Freundlich (gray) isothermal model (c =5 ppm, T=303K, stirring rate=500 rpm, n=3).\nAZN\nComment 6: During the process of charging-discharging electrocatalysis, the\ndegradation in discharging period was the main emphasis. In addition to DEMS, it\nshould be added the removal efficiency of AZN during a charging-discharging process,\nwhich could reflect the degradation during the discharge process.\nResponse: Thank you for your comments. In the revised manuscript, we have further\nclarified the degradation efficiency during the discharging stage. In addition to the\nDEMS evidence already presented in Supporting Information (Supplementary Fig. 11),\nwe added control experiments by comparing a full charging-discharging process with a\n“charging-pulse-OCP” protocol, in which the stored charge of c-MIP was released by a\nstage (Supplementary Fig. 20b). Although the degradation during discharging stages\nwas slightly slower than during charging stages, it still contributed significantly to AZN\nremoval (Supplementary Fig. 20a). In contrast, the control without the discharging\nstage (“charging-pulse-OCP”) exhibited a much weaker removal performance, further\nconfirming that pollutant degradation occurs effectively during the discharging process.\nThe corresponding results and discussion have been added in the revised manuscript.\nRevision: In Lines 249-251, “By employing denser sampling during the discharge\nperiod, we further confirmed that AZN was substantially degraded in the discharging\nstage itself (Supplementary Fig. 20a). In contrast, a control charging-pulse procedure\nthat disabled the discharging phase (gray line in Fig. 4e and Supplementary Fig. 20)\nresulted in much lower removal rates, underscoring the critical role of discharging-\nassociated catalysis.” has been added.\nSupplementary Fig. 20 a Removal of AZN by C-MIP in the “charging-pulse-OCP” processes\n(black) and “charging-discharging” processes (red) b-c Electrochemical procedures of the\n“charging-pulse-OCP” processes (b) and “charging-discharging” processes (c)\nComment 7: The imprinted polymers were used for the selectively absorption of\ntargeted compounds. Could conductive molecularly imprinted polymer work for\nemerging contaminants other than azithromycin? Please discuss the general\napplication potential of this strategy for emerging contaminants treatment.\nResponse: Thank you for this insightful comment. In response, we extended our study\nto several ECs beyond azithromycin and found that the c-MIP strategy was generally\neffective for ECs containing hydroxyl or carboxyl groups, as demonstrated for\ntetracycline (TET) and diclofenac (DCF). However, its performance was limited for\namino-group-containing pollutants such as sulfamethoxazole (SMX), due to the slower\nkinetics of amide bond formation. We have revised the manuscript to discuss both the\ngeneral applicability and the current limitations of this approach.\nRevision: In Lines 329-350, “Furthermore, the c-MIP platform was extended to\nvalidate its capability for selectively enriching diverse ECs. For ECs containing\nhydroxyl groups like TET, a c-MIP was constructed using 3-TBA as the functional\nmonomer, enabling the formation of boronate ester bonds with hydroxyl groups of TET\n(Supplementary Fig. 35a). The resulting c-MIP exhibited strong selectivity toward TET\n(Supplementary Fig. 35b), with minimal interference from DCF and SMX. Similarly,\nfor ECs containing carboxyl groups like DCF, 3,4-diaminothiophene (3,4-NH -Th) was\n2\nemployed as the functional monomer to form amide bonds (Supplementary Fig. 35c).\nAlthough its overall efficiency was slightly inferior to the c-MIPs developed for MLs\nand TET (Supplementary Fig. 35d), these results confirm that amide bond formation is\na viable strategy for imprinting carboxyl-containing contaminants. However, targeting\namino-group-containing ECs such as SMX proved more challenging. A c-MIP prepared\nwith 3,4-thiophenedicarboxylic acid as the functional monomer was designed to form\namide bonds with SMX (Supplementary Fig. 35e), while the resulting polymer failed\nto effectively distinguish SMX from TET (Supplementary Fig. 35f). This reduced\nselectivity can be attributed to the slower kinetics of amide bond formation with amino\ngroups, while TET, bearing multiple hydroxyl groups, rapidly formed stable boronate\nesters, thereby outcompeting SMX and dominating the binding sites. Taken together,\nthese results indicated that the c-MIP strategy can be readily adapted by tailoring\ntemplate molecules and selecting complementary functional monomers, thereby\nenabling selective enrichment of ECs containing hydroxyl or carboxyl functional\ngroups.” has been added.\nSupplementary Fig. 35 Construction of c-MIP towards TET (a), DCF (c), and SMX (e) and\nadsorption removal of these c-MIPs to targeted ECs over interferences (b, d, f). c =c =c =\nTET DCF TET\n1 ppm, T=303 K, stirring rate=500 rpm, n=3.\nComment 8: The degradation reaction takes place around the surface of electrode.\nPollutant diffusion to the electrode surface from the dilute solution is importance for\nemerging contaminants treatments. What is the key driving factor of dilute emerging\ncontaminants to electrode surface? How to overcome this diffusion barrier in this work?\nMore evidences are needed to discuss this point.\nResponse: Thank you for this constructive comment. To address it, we performed\nadsorption experiments of c-MIP toward AZN under different stirring speeds (0-1000\nrpm) and initial concentrations (0.5-10 ppm). Higher stirring rates markedly accelerated\nadsorption kinetics (Supplementary Fig. 41), confirming that external mass transfer\nplays a key role in dilute systems. In addition, the adsorption capacity increased with\npollutant concentration, demonstrating that the concentration gradient is the primary\ndriving force for pollutants to approach the electrode surface.\nBeyond this generic diffusion-driven mechanism, our c-MIP exhibited a unique\nadvantage that the imprinted cavities were equipped with functional monomers capable\nof forming reversible covalent bonds (e.g., boronate esters) with the target pollutants.\nThese strong and specific interactions allowed the rapid capture of trace molecules once\nthey reached the electrode surface and simultaneously suppressed their desorption,\nthereby shifting the adsorption-desorption equilibrium toward efficient enrichment. It\nwas also supported by the DFT results in Fig. 5e. The corresponding data and discussion\nhave been added in the revised manuscript.\nRevision: In Lines 385-397, “To further clarify the driving factors enabling dilute\ncontaminants to approach the electrode surface, adsorption experiments of AZN were\nconducted under different stirring rates (0-1000 rpm) and initial concentrations (0.5-10\nppm). Higher stirring rates significantly accelerated adsorption kinetics\n(Supplementary Fig. 41), indicating that external mass transfer was important in dilute\nsystems, while the adsorption capacity increased with concentration, confirming the\nconcentration gradient as the primary driving force. These results provided direct\nevidence supporting the effective enrichment of trace pollutants by c-MIP electrodes,\nbeyond the molecular recognition effect. More importantly, beyond these generic\neffects, c-MIP provided a unique advantage over conventional adsorption materials.\nThe imprinted sites can form reversible covalent linkages with target molecules,\nenabling rapid capture and suppressing desorption, thereby shifting the adsorption-\ndesorption equilibrium toward efficient enrichment.” has been added.\nSupplementary Fig. 41 a Adsorption curves of the c-MIP towards 5 ppm AZN at different\nstirring rates b Adsorption curves of the c-MIP towards 0.5-10 ppm AZN at 500 rpm. (T=303\nK, n=3)\nResponse to Reviewers’ Comments\nReviewer #1 (Remarks to the Author):\nAll my quires have been addressed in the revision, and it can be accepted.\nResponse: We are glad that we were able to address your comments.\nReviewer #2 (Remarks to the Author):\nThe revised addressed my concerns.\nResponse: We are glad that we were able to address your concerns.\nReviewer #3 (Remarks to the Author):\nI co-reviewed this manuscript with one of the reviewers who provided the listed reports.\nThis is part of the Nature Communications initiative to facilitate training in peer review\nand to provide appropriate recognition for Early Career Researchers who co-review\nmanuscripts.\nResponse: Thank you very much for your time involved in reviewing the manuscript\nand your very encouraging comments on the merits.\nReviewer #4 (Remarks to the Author):\nAuthors have revised the manuscript according to our comments. The submission has\nimproved and could be accepted.\nResponse: Thank you for your kind words and we are glad that we were able to address\nyour comments."}, {"round": 2, "reviewer_comments": {"reviewer_1": "All my quires have been addressed in the revision, and it can be accepted.", "reviewer_2": "The revised addressed my concerns.", "reviewer_3": "I co-reviewed this manuscript with one of the reviewers who provided the listed reports. This is part of the Nature Communications initiative to facilitate training in peer review and to provide appropriate recognition for Early Career Researchers who co-review manuscripts.", "reviewer_4": "Authors have revised the manuscript according to our comments. The submission has improved and could be accepted."}, "author_response": ""}]

Decision letter