bluuebunny/crossref_metadata_2025 huggingface dataset:
The Additive to Mass Manufacturing Process of Mixed Potential Electrochemical Sensors
Authors: Halley Sleight , Ramaiyan Kannan , Tsui Lok-kun , Garzon Fernando H.
Published: August 2024

Additive manufacturing allows for quick turn around and low cost of production of small numbers of parts. These attributes lend the technology to prototype development, where design changes are many and production numbers are low [1]. Once design parameters have been nailed down, additive manufacturing’s low throughput and poor reproducibility limit application to high volume production.

Here, we discuss the implementation of direct-write extrusion of ceramic pastes and metal inks for prototype manufacturing of mixed potential electrochemical sensors and the transition to tape casting and screen printing for high volume production. Throughout the prototyping phase, direct write extrusion enabled quick and easy production of low numbers of parts, enabling various changes in sensor design and material to improve sensor performance. Sensor design evolved from a disk shape (Fig. 1 a) to a stick with integrated heater (Fig. 1 b, c). Direct write extrusion of substrate enabled quick testing of various stabilized zirconia ceramics to improve the sensitivity of the device [2]. Limitations of additive manufacturing became apparent when attempting to integrate the heater into the device, the inconsistent linewidths led to areas of high resistance and hot spots (Fig. 1 c). Tape-casting and screen printing of the devices was adopted for three reasons, first, to improve line fidelity, which is vitally important when printing small electrodes as well as heater traces (Fig. 1 d), second, to further decrease conductivity of substrate by laminating multiple layers of different ceramic materials, and finally to increase manufacturing throughput (Fig. 1 d, e).

This work was supported by US Department of Energy Award DE-FE0031864

References

[1] T. D. Ngo, A. Kashani, G. Imbalzano, K. T. Q. Nguyen, and D. Hui, “Additive manufacturing (3D printing): A review of materials, methods, applications and challenges,” Compos. Part B Eng., vol. 143, pp. 172–196, Jun. 2018, doi: 10.1016/j.compositesb.2018.02.012.

[2] S. Halley, K. Ramaiyan, F. Garzon, and L. Tsui, “Massive enhancement in sensitivity of mixed potential sensors towards methane and natural gas through magnesia stabilized zirconia low ionic conductivity substrate,” Sens. Actuators B Chem., vol. 392, p. 134031, Oct. 2023, doi: 10.1016/j.snb.2023.134031.

Figure 1
Wearable Microneedle Biosensor for Real-Time I-Situ Antibiotic Monitoring
Authors: Keyvani Fatemeh , Poudineh Mahla
Published: August 2024

Current methods for therapeutic drug monitoring (TDM) have a long turnaround time as they involve collecting patients' blood samples followed by transferring the samples to localized medical laboratories where sample processing and analysis are performed. To enable real-time and minimally invasive TDM, we have developed a microneedle (MN) biosensor to monitor the levels of two important antibiotics, vancomycin (VAN) and gentamicin (GEN). The MN biosensor is composed of a hydrogel MN (HMN), and an aptamer-functionalized flexible (Flex) electrode, named HMN-Flex. The HMN extracts dermal interstitial fluid (ISF) and transfers it to the Flex electrode where sensing of the target antibiotics happens. The HMN-Flex performance has been validated in-vitro using skin models as well as in-vivo in live rat animal models. Furthermore, we leveraged data from the HMN-Flex system to construct pharmacokinetic profiles for VAN and GEN and compared these profiles with conventional blood-based measurements.
Development of an Aptamer-Modified Wearable Biosensor for Early Detection of Traumatic Brain Injuries
Authors: Vazquez Yolimar , Cunci Lisandro , Santana Alicea Dasairy L
Published: August 2024

Traumatic brain injuries (TBI) can significantly alter brain function and present as a critical, potentially life-threatening condition necessitating prompt identification and ongoing monitoring. Categorized as mild, moderate, or severe, TBIs often manifest challenging post-injury symptoms. Despite scientific advancements, the methodologies for TBI identification, evaluation, and monitoring have remained largely unchanged for the past 50 years. To address this, our proposal focuses on creating an electrochemical biosensor for the early detection of glial fibrillary acidic protein (GFAP), a crucial biomarker associated with TBI. Our approach involves employing the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technique to develop a highly specific aptamer for GFAP detection. The biosensor will utilize aptamer-modified electrodes with a carbon-based substrate to enable continuous real-time detection of the target. By detecting GFAP, our biosensor aims to mitigate risks associated with injury-related damage, exposure to ionizing radiation, and healthcare expenses. Moreover, our proposed strategy seeks to advance our comprehension of GFAP release and its role in early TBIs, potentially paving the way for future in vivo studies. To enhance the biosensor's long-term stability, our design centers on a carbon-based nanomaterial substrate. Carbon-based nanomaterials have gained prominence in biosensor applications due to their diverse properties, including conductivity, chemical stability, mechanical strength, surface-to-volume ratio, biocompatibility, functionalization, and biodegradability. Our biosensor's advancement will employ electrochemical impedance spectroscopy (EIS), fast scan cyclic voltammetry (FSCV), and square wave voltammetry (SWV) for electrochemical testing. Electrochemistry offers numerous advantages over light-based detection methods, allowing for enhanced electrode surface modification to improve selectivity and flexibility. This adaptability positions our biosensor as an ideal candidate for wearable applications in field settings, capable of detecting a broad spectrum of molecules beyond oxidation or reduction reactions. The successful realization of these objectives will result in a GFAP-detecting biosensor. Our proposed experiments aim to bridge existing gaps by developing a novel device for non-invasively measuring biomarkers released through sweat, thereby contributing to innovative diagnostic approaches.

Figure 1
Fabric and Fiber-Integrated, Washable Hydrogel Electrodes for Clinically Accurate Sleep Monitoring in-Home
Authors: Andrew Trisha L.
Published: August 2024

Longitudinal tracking of sleep metrics is important for detecting and managing various diseases, spanning cardiorespiratory disorders to dementia. However, at present, sleep monitoring primarily occurs in specialized medical facilities that are not conducive to longterm studies. In-home solutions either compromise user comfort or signal accuracy in tracking sleep variables and have not yet provided reliable longitudinal data. We believe that human-centered design of multimodal, low-form-factor, comfortable sensing systems is needed for this increasingly-important area of preventative health monitoring. Our lab developed a suite of fabric-based and/or garment-integrated sensors and sensing modalities that accurately and reliably extract important sleep metrics, such as posture, cardiorespiratory signals, eye movement and brain activity, over the course of an eight-hour sleep session. Our garment-integrated sensing arrays do not require a medical professional for on-body positioning, maintain their function independent of sizing and fit on individual users, and can be laundered or cleaned with antibacterial wipes without compromising its varied sensing elements. Here, we describe one of these two key sensors, a fabric or fiber-based electrochemical hydrogel electrode that enables wearable biopotential monitoring, including electrocardiography (ECG), eletrooculography (EOG) and electroencephalography (EEG), from which the aforementioned sleep metrics can be recorded and quantified with clinical precision and accuracy. The hydrogel is fabricated as a coating on either commodity fabrics or threads using a low-temperature reactive deposition process, termed photoinitiated chemical vapor deposition (piCVD), during which hydrogel monomers react with a photoinitator in the vapor phase to create a polymeric hydrogel coating directly on the surface of fabrics or threads that have been temporarily surface modified with a skin-safe electrolyte gel. The resulting composite hydrogel coating isolated from this operation is ionically conductive, can be reversibly swelled in water and dried without losing ionic conductivity, and transduces the ionic signals (fluxes) experienced by the body into an electrical signal that can be captured by any commercial ECG, EOG or EEG monitoring instrument. An array of these fabric or thread-based hydrogel electrodes can be integrated into readily-available garments using simple cut-sew techniques and these garments can then be worn throughout the night to effect continuous ECG, EOG and EEG monitoring at home. Design elements of a custom-made circuit board that allows simultaneous capture of these signals will be described. Results from an ongoing user study of >50 adults will be presented to validate the clinical precision and accuracy of these garment sensor for sleep quality monitoring.
Traces of Ions Sensing and Tracking in Support of Green H2 Economy and Sustainability
Authors: Dong Dongmei
Published: August 2024

Given the focus on a green H2 economy for a sustainable future, it is crucial to understand the degradation features of H2-focus electrochemical devices and systems, i.e., proton exchange membrane fuel cells and water electrolysis (PEM-based FC & WE). The current accelerated stress test and resulting degradation features are systematically investigated through comprehensive analysis, including a series of electrochemical, spectroscopic, tomographic, and microscopic characterization, assisted with a detailed structure examination of the electrode, membrane, and interface. However, numerous characteristic studies that aim to uncover these features under various dynamic operations are commonly employed to depend on the sophisticated laboratory stationary bulky facilities and instruments in the theater. Moving forward to real-world practical applications, i.e., H2 electrical vehicles, a miniaturized, mobile, low-cost, and user-friendly measurement and diagnostic tool is highly in demand. Considering the dependence of the performance and durability on the ion exchange/transport, and involvement of small particles, and the high possibility of dissolution, the time-dependent sensing and tracking of such traces of ions can provide fundamental insight into the activities and events within the PEM-based FC & WE devices and systems. Our recent efforts are dedicated to bridging the notable gap to develop electrochemical and transistor-based ion sensors integrated on a circuit chip towards real-time in-situ monitoring of the health and degradation status. This complementary work may also provide valuable guidelines for establishing a suitable accelerated stress test protocol to diagnose system durability, and for designing durable materials for long-term operation.
Ultrasonic Analysis for Monitoring Li-Ion Batteries
Authors: Milano Lorenzo , Magagnin Luca
Published: August 2024

To seek for increasing accuracy in LIBs monitoring a new trend is to rely on data indicative of material properties whose variations are induced by Li ions intercalation and deintercalation. A wider variety of information can be achieved if data are referred to a specific layer of the battery. Since ultrasounds propagate at different speed according to materials properties and are reflected every time they hit an interface, ultrasonic analysis (UA) has the potential to improve the quality of LIB monitoring providing in operando and through thickness information.

In this work NMC-graphite LIBs are cycled and monitored in operando via UA in pulse-echo and through-thickness modes with a temporal resolution of 7 ns (which to the best of our knowledge is the highest ever tested) and a 5 MHz frequency. First, the effect of (i) temperature and (ii) C-rate on the waveform evolution was investigated: (i) a 100% charged battery was kept at rest in a thermal chamber at fixed temperatures varying between 10 and 50°C, the ultrasonic signal was acquired after 30 min at rest; (ii) an initially 100% charged battery underwent two subsequent discharge-charge cycles at constant current with fixed C-rates varying between 0.2 and 2C. Then a series of cycles at 50°C aimed at causing battery degradation was performed while acquiring the ultrasonic signal every 2 min. The efficacy of the degradation protocol was assessed through EIS prior and post cycling the battery. Surprisingly, results show an opposite (but systemic) trend with respect to what is reported in literature, with an increasing time of flight (ToF) for increasing state of charge (SoC). Additionally, it is observed that most of the peaks increase their ToF with the number of cycles. Signal amplitude shows a periodical behavior as well but values vary as degradation has gone on. It is also observed that within a cycle some peaks increase their intensity during charge while others decrease, suggesting that they belong to opposite electrodes.
Electrochemical Detection of Bisphenol a By Modified Gold Electrode with Ternary Quantum Dot Metal Organic Framework Composites
Authors: Ajibade Peter A , Oloyede Solomon O , Rajeshwar Krishnan
Published: August 2024

Modified gold electrode with Metal-organic framework (MOFs), ternary quantum dots (TQDs) and their composite (TQDs@MOFs) were as electrochemical sensor to determine bisphenol A (BPA). A comparative electrochemical study of the MOFs, QDs and QDs@MOFs reveals that the composite (QDs@MOFs) have the highest conductivity, largest effective surface area, lowest peak potential separation (∆Ep) and the highest oxidation peak current. Under optimal conditions and wide range of BPA concentrations, the ternary quantum dots metal organic frameworks were a better sensor for bisphenol A with 0.488 nM limit of detection and 1.473 nM. limit of quantitation in comparison to metal organic framework and quantum dots. The results show that QDs@MOFs responded remarkable to BPA and could be adapted a practical and efficient efficient sensor for the determination of BPA
Chemical Substitution Strategies for Tailoring P2- and O3-Type Layered Oxide Cathodes in Sodium-Ion Batteries
Authors: Ghosh Arindam , Senthilkumar Baskar , Hegde Rashmi , Ghosh Subham , Amonpattaratkit Penphitcha , Senguttuvan Premkumar
Published: August 2024

Among cathodes for sodium-ion batteries (SIBs), layered transition metal oxides Na
x
MO2 (M = transition metal) are very promising due to their easy synthesis and high theoretical capacity.1,2 In this class, Ni/Mn/Fe-based layered oxides are attractive due to the high redox potential of Ni2+/ Ni4+ and Jahn Teller inactive centers (Ni2+, Fe3+,and Mn4+).3 However, complex phase transitions, Na+/vacancy ordering and transition-metal (TM) migration degrade their electrochemical performances.4 To address the issues, a widely studied cathode- P2-type Na0.67[Ni0.33Mn0.67]O2 is chosen and Li+ is substituted in the TM-layer to tailor a series of high Na-content cathodes. Among them, Na0.85[Li0.14Ni0.29Mn0.57]O2 cathode with optimal Li-substitution exhibits a reversible capacity of 168 mAh g-1 at 0.1 C rate and good cycling stability (82% retention after 100 cycles).5
In-situ XRD measurement reveals a complete solid-solution formation and X-ray absorption spectroscopy studies confirm the participation of Ni4+/Ni2+ and Mn4+/Mn3+ redox couples during Na+-extraction/insertion. Lastly, a full Na-ion cell with hard carbon is demonstrated with an energy density of 420 Wh kg-1. In subsequent work, a Li and Ti co-substitution strategy is applied to design a high-entropy O3-type NaLixNiyFezMn0.5Ti0.5-aO2 cathode.6 It retains 77% of its initial capacity after 400 cycles at a 2 C rate with a facile O3-P3-OP2-P3-O3 phase transition. The co-substitution strategy uplifts the average voltage of the system, improves the reversibility of the high-voltage OP2 phase, and enhances the Na-ion diffusion rate. A mere 1.32% unit cell volume change and diminishing electrochemical cell resistance over cycling ensure its superior long-term cycling performance. A full cell is fabricated, which holds 62% of its initial capacity even after 1000 cycles at a 0.5 C rate. Therefore, mono- and di-ion substitution strategies hold enormous potential for designing high-performing P2- and O3-type cathode materials for practical SIBs.

References

T. Hosaka, K. Kubota, A. S. Hameed, and S. Komaba, Chem. Rev., 120, 6358–6466 (2020).

J. Y. Hwang, S. T. Myung, and Y. K. Sun, Chem. Soc. Rev., 46, 3529–3614 (2017).

F. Zhang, J. Liao, L. Xu, W. Wu, and X. Wu, ACS Appl. Mater. Interfaces, 13, 40695–40704 (2021).

Z. Lu and J. R. Dahn, J. Electrochem. Soc., 148, A1225 (2001).

A. Ghosh, B. Senthilkumar, S. Ghosh, P. Amonpattaratkit, and P. Senguttuvan, J. Electrochem. Soc., 170, 030538 (2023).

A. Ghosh, R. Hegde, and P. Senguttuvan, J. Mater. Chem. A., submitted(2023).
Effect of Ni Concentration on Physical Properties in Electroformed Fe-Ni Alloy for ACC of Secondary Battery
Authors: Lee JUN HA , KIM In Gyeong , Shin Se Eun , Park Yong-bum
Published: August 2024

The anode current collectors (ACC) work as a support for electrode materials. They are also electrical conductors between electrode and external circuits. Usually copper ∙ nickel ∙ titanium ∙ 304 stainless steel materials are used as ACC due to high electrical conductivity, high mechanical and thermal stability in the potential range of 0~2.96 V. Contrary to copper and nickel, electroformed Fe-Ni alloy is a promising materials due to obtain such as high mechanical strength, low cost, and producing very thin ACCs. In the current work, Fe-Ni alloys were electroformed by employing batch-type electrodeposition simulating the drum-type cathode for continuous electroforming equipment. During thermo-mechanical anneaing, the decrease lattice parameter of the γ phase occurred and AGG were observed on electroformed Fe-40~80 wt.% Ni alloys. The current work has been aimed at investigating the effect of the Ni concentration on the physical properties of the electroformed Fe-Ni alloy.
Effect of Lithiation and Delithiation on the Mechanical Properties of Electrodeposited LiCoO2 Cathode
Authors: Wang Yingjin , Juarez Yescaz Carlos , Kwon Patrick , Zahiri Beniamin , Braun Paul V. , Greer Julia R.
Published: August 2024

Mechanical degradation of cathode active material, such as cracks result from volume changes and phase transitions, is one of the main causes of capacity fading in lithium-ion batteries. Understanding the active material’s deformation behavior during cycling and the impact of electrochemical charging on mechanical properties is crucial for understanding the mechanical degradation mechanism and extending battery lifetime.

Herein, we investigate the mechanical properties of an electroplated LiCoO2 (LCO) cathode with crystallographic texture as a function of state of charge/discharge. Nanoindentation mapping is used to detect the differences in mechanical behavior between grain boundary and grain interior region. To determine the charged LCO crystals’ mechanical properties and avoid the effects from grain boundaries and air-exposure, in-situ nanoindentation experiments are conducted in a custom mechanical testing system within a scanning electron microscope. Considering the anisotropy of LCO, electron backscatter diffraction analysis is utilized to clarify the crystallographic orientation of the electrodeposited LCO cathode. Our result shows a decreasing tendency in elastic modulus and hardness with state of charge, which can be attributed to the expansion of LCO layered structure. The recovery of mechanical properties after discharge indicates that the changes in measured mechanical properties mainly come from Li deintercalation and intercalation rather than intergranular fracture during cycling. By releasing the relationship between mechanical properties and degree of delithiation, our study provides an insight into modeling studies of electro-chemo-mechanics for electrode materials.

Figure 1
Effect of Halide Ion Additives during Electrodeposition of Nanocatalysts
Authors: Hadley Annabelle M. K. , Gautam Sakshi , Gates Byron D.
Published: August 2024

Platinum (Pt) and platinum ruthenium (PtRu) alloy catalysts are of interest for the development of green energy technologies such as hydrogen and direct methanol fuel cells. However, the high cost of Pt dictates that the precious metal be used as efficiently as possible so the surface area available to catalyze reactions per mass is maximized. Alloying Pt with different metals such as Ru is also of interest due to the increased activity and tolerance to contaminants that the additional metal imparts to the Pt. Industrial nanoparticle synthesis depends on scalable techniques such as electrodeposition. And a feature of this technique is that the morphology of electrodeposited structures is heavily influenced by the composition of the electrodeposition solution.

This work describes how the presence of excess Cl- and Br- ions in an aqueous solution of metal salts affects the morphology of Pt and PtRu electrodeposited onto glassy carbon electrode substrates. The addition Br- ions and mixtures of the two halides resulted in smaller nanoparticles as observed by scanning electron microscopy and, therefore, higher surface areas compared to Pt electrodeposited in the absence of these halide species. Consequently, the mass activity towards the oxygen reduction reaction, one half of the reaction in hydrogen fuel cells, was highest when Pt was electrodeposited in the presence of Br- ions. The PtRu particles were also tested for their activity and resistance to carbon monoxide poisoning as a function of composition and halide additives. These results show that halide ions can be used beneficially in electrocatalyst synthesis without a negative impact on the activity of these catalysts, in contrast to what has been suggested in some prior studies. Presented herein is a simple method to tune the surface area and properties of electrodeposited nanocatalysts.1

Gautam, S.; Hadley, A. M. K.; Gates, B. D. Controlled Growth of Platinum Nanoparticles during Electrodeposition using Halide Ion Containing Additives. J.
Electrochem. Soc.
2022, 169, 112508.
Optimizing the Performance of Nickel Electrocatalysts with Regular Arrays of Linear Ridge-like Features for Enhancing the Oxygen Evolution Reaction
Authors: Rea Alex J. G. , Pauls Alexi L. , Taylor Audrey K. , Gates Byron D.
Published: August 2024

The oxygen evolution reaction (OER) represents a major source of inefficiency in the production of green hydrogen via electrocatalytic water splitting. At high overpotentials relevant to industrial rates of gas production, bubbles can contribute substantially to these inefficiencies by inhibiting the mass transport of electrolyte and partially obstructing the electrochemically active surface area (Aecsa) of an electrode.1 Arrays of microscale features have been shown to improve the efficiency of gas evolving reactions, including the OER. The performance of electrodes modified with linear ridge-like surface features has been previously observed to increase with the spacing between the ridges with a separation of up to 200 µm, but it was not known whether this trend continues indefinitely.2 The present study utilizes rapid prototyping techniques, including microscope projection photolithography and electrodeposition, to determine whether an optimal ridge separation exists between 200 and 450 µm. At a relatively high overpotential of 1.8 V (vs Hg/HgO) in an alkaline electrolyte, the performance of these ridges was observed to increase up to a critical separation, after which the performance decreased to a level comparable to a planar electrode at a wider separation between the ridges. Chronoamperometry measurements indicated that ridges with this optimal spacing attained a current response nearly 3× that of a planar electrode when normalized to (Aecsa). A better understanding of the reasons for this observed trend was pursued using high speed imaging. Direct observations of bubble production on the surfaces of the electrodes provided a deeper understanding of how the distribution of gas bubbles on an electrode affects performance.

References:

Angulo, A.; van der Linde, P.; Gardeniers, H.; Modestino, M.; Fernández Rivas, D. Influence of Bubbles on the Energy Conversion Efficiency of Electrochemical Reactors. Joule
2020, 4 (3), 555–579.

Taylor, A. K.; Mou, T.; Sonea, A.; Chen, J.; Yee, B. B.; Gates, B. D. Arrays of Microscale Linear Ridges with Self-Cleaning Functionality for the Oxygen Evolution Reaction. ACS Appl. Mater. Interfaces
2021, 13 (2), 2399–2413.
Fabrication of Bipolar Membrane Electrolyzers for Seawater Electrolysis: Proof-of-Concept, Operando Design, and Fundamental Studies
Authors: Ríos Isabela , Hannagan Ryan Travis , Marin Daniela , Perryman Joseph T. , Burke Stevens Michaela , Nielander Adam C , Jaramillo Thomas F.
Published: August 2024

Hydrogen (H2) is a critical industrial feedstock, essential in the production of fertilizer, steel, and fuels. Its demand is anticipated to increase ten-fold by 2050 due to its pivotal role in various new green technologies. Renewable energy-driven bipolar membrane water electrolyzers (BPMWEs) are a promising technology for sustainable production of H2 from seawater and other impure water sources. Here we present a detailed protocol on the assembly and operation of zero-gap membrane electrode assembly (MEA) BPMWE with water dissociation layers1. We describe steps for spray coating both electrodes and membranes, electrolyzer assembly, and electrochemical evaluation. This protocol provides an avenue to highlight key considerations in BPMWE fabrication methodology to ensure comparable data and rapid progress. We further highlight how this BPM platform can be used for a variety of scientific applications ranging from the seawater resistant BPMWE to an operando water electrolyzers to examine catalyst dynamics through X-ray absorption spectroscopy (XAS). As we work together towards a cleaner future, the detailed BPMWE protocol enables scientific communication, aiding in reproducible electrolyzer assembly practices, and accelerating the optimization of next-generation BPM-based devices.
Effect of the Saccharin Concentration on Electrodeposition of the Fe-Ni Alloy
Authors: Kim Jin Bum , KIM In Gyeong , Park Yong-bum , Shin Se eun , Lee Seung-Joon
Published: August 2024

The FMM (Fine Metal Mask) used in the OLED display manufacturing process is a metal sheet with holes formed to allow the deposition of diode material only in the sub-pixel area. To prevent deformation and misalignment of the FMM (Fine Metal Mask) caused by heat during the RGB organic deposition process, an Invar plate with a thermal expansion coefficient (CTE) close to 0 is used. The Invar sheet applied to the current FMM is manufactured through a metallurgical process, and its final thickness after rolling is 20 micron. However, due to limitations in reducing thickness with the rolling process, for manufacturing FMM with a thickness of under 10 micron for next-generation high-resolution (UHD-level) displays, the bottom-up electroplating process is suitable. However, to maintain the shape of the electroplated Invar sheet while ensuring commercial-grade low CTE, heat treatment at temperatures exceeding 600℃ for an extended period is required, utilizing thermo-mechanical processing methods. If uniformity in the microstructure composed of nano-grains is ensured in the electroplated Invar alloy in the As-deposited, it is possible to increase the efficiency of the process by reducing the heat-treatment processing cost.

Therefore, in this study, we investigated the microstructural evolution in the Invar alloy by controlling the surface stress of the electroplated layer during pre-plating. We controlled the key additive, saccharin, in the Fe-Ni alloy electrolyte to assist the diffusion of iron and nickel ions. By examining the relation between microstructural uniformity, determined by the plated layer, and CTE, we propose optimized process conditions for the pre-plated Invar sheet.
One-Pot Electrosynthesis of Gamma-Butyrolactone (GBL) from Biomass-Derived Furoic Acid
Authors: Liu Shengqin , Lam Jason Chun-Ho
Published: August 2024

An efficient catalytic method to transform biomass into value-added products is critical to promoting a sustainable future. Ideally, such a transformation should be carried out efficiently in mild conditions. Herein, we developed a mild one-pot electrochemical protocol for converting furoic acid (FA), a common biomass-derived feedstock, into a versatile platform chemical, gamma-butyrolactone (GBL). All involved species participate in the desired redox pathway with high selectivity: FA was electrochemically oxidized with 84.2% selectivity to 2(5H)-furanone, the olefin of which was then hydrogenated to yield GBL with 98.5% selectivity. We identified that a specific temperature is an essential factor in enabling the one-pot reaction as it promotes thermal desorption of the key intermediate. The reaction was scalable to gram-scale, producing high-purity GBL isolated through a simple solvent extraction from a 500-mL electrolysis scale reaction.
Application of Bifunctional Layered Double Hydroxide Electrocatalysts to Water Splitting
Authors: Ennis Colm , Alves Daniele , Dempsey Eithne , Breslin Carmel B
Published: August 2024

Water splitting is an area of research which is of pressing interest in addressing climate change. Water splitting provides oxygen and hydrogen as products, with hydrogen finding use as a potential high-density fuel to replace fossil fuels. Water splitting manifests as two half-cell reactions, namely the anodic oxygen evolution reaction and the cathodic hydrogen evolution reaction. The purpose of this project is to synthesise a bifunctional electrocatalyst to use in the water splitting reaction, replacing the rare and expensive transition metals catalysts currently in use such as platinum and ruthenium. The ideal material would exhibit strong performance for both the oxygen evolution reaction and the hydrogen evolution reaction.

In this project, Layered Double Hydroxides (LDHs) have been synthesised for use in water splitting. LDHs are a group of ionic compounds characterised by their layered structure of positively charged sheets and an interlayer region consisting of the corresponding anions. LDHs typically contain a bivalent and a trivalent metal as part of the generic formula [M2+
1–xM3+
x(OH)2][An–]x/n·zH2O. In this project the bivalent metal in use is typically cobalt and the trivalent metal is typically iron. The synthesis developed is a simple, one pot hydrothermal synthesis which can be seen in Figure 1. In this synthesis, the process begins with the precursor materials dissolved in solution. These solutions are mixed and stirred until homogenous. The resultant solution is then heated to form an impure product. Following washing steps and centrifugation a purified powder product is obtained. A variety of metallic salts have been tested for their use in these LDHs with the optimum LDHs selected for further study. The metallic salts used to provide the metals for the LDHs are typically hydrated transition metal nitrates.

The LDHs have been characterised and their structure confirmed by a variety of analytical techniques including X-Ray Diffraction and Scanning Electron Microscopy. Simple qualitative analysis has been performed with FTIR spectroscopy. These LDHs have been immobilised on a variety of porous, high surface area materials, including nickel foam and copper foam, to enhance the properties seen in the screening study. These materials allow synthesis of high surface area, reactive electrocatalysts. To enhance the stability of the LDHs, carbon materials have been integrated with the LDHs. Examination of a variety of carbon materials involved post-synthesis mixing of the carbon material and the LDH product or inclusion of the carbon material in the LDH synthesis to form a composite. A variety of carbon materials have been analysed including graphene oxide, carbon black and carbon nanotubes.

Figure 1
Synthesis of Plasmonic Copper/Copper Oxide Nanostructures as (Photo)Catalysts
Authors: Salmanian Ghazaleh , Chen Jingyi
Published: August 2024

Plasmonic nanostructures can enhance the photocatalytic efficiency of semiconductors under visible light irradiation. While the plasmonic-enhanced photocatalysis has been widely studied, rigorous efforts focus on designing novel noble metal nanostructures by altering particle size, shape, and composition to optimize their interaction with light to influence the catalytic properties. However, the need for a more cost-effective material as an alternative for noble metals has led us toward the exploration of copper and their oxides for photocatalysis. In this work, we synthesize different morphologies of copper nanostructures (i.e., 10 nm and 50 nm nanoparticles, as well as nanowires. Copper nanostructures are prone to be oxidized over time; however, the degree of oxidation varies with the size and shape of the nanostructure, thereby creating hybrid copper/copper oxide nanostructures with unique optical and (photo)catalytic properties. The hybrid nanostructures are characterized by X-ray powder diffraction and transmission electron microscopy. Their optical properties are studied by UV-vis spectroscopy along with simulation. We then further study the use of these hybrid nanostructures as (photo)catalysts for redox reactions – the reduction of 4-nitrophenol (4-NP) and the oxidation of tetramethylbenzidine (TMB). The (photo)catalytic properties will be correlated with the size, shape, and the degree of oxidation of these hybrid nanostructures. The mechanisms of both reactions on the hybrid copper/copper oxide (photo)catalysts will be discussed.
Electrochemical Hydrogenation of Refractory Organics in Wastewater
Authors: Shao Shan , Lam Jason Chun-Ho
Published: August 2024

Wastewater treatment is an essential process for the sustainable development of a society. The handling and degrading of different refractory and toxic organic pollutants heavily relies on conventional biodegradation. Herein, we developed an electrochemical hydrogenation method to enhance the biodegradability of organic substrates, which subsequently improves their availability to other biological-driven processes, namely denitrification. The strategy presents an unprecedented "kill-two-birds-with-one-stone" strategy to simultaneously deal with excessive organic components and nitrate's presence in wastewater. The strategy was discovered by comparing the biodegradability of some organic compounds and their hydrogenation forms. It was found that the hydrogenation product was much more bioavailable. Motivated by this discovery, we synthesized a carbon-supported Ru electrode by electrodepositing Ru on activated carbon cloth (ACC), named Ru/ACC. After that, 4-chlorophenol was used to optimize the experimental conditions, and Ru/ACC electrodes successfully converted 99.9% of 4-chlorophenol with an overall yield reached 90.9%. After that, the Ru/ACC electrodes proved efficient in transferring various wastewater organic pollutants. Besides, the electrochemical hydrogenation effect on biochemical degradation and denitrification was studied. It is significant for the electrochemical hydrogenation method to be applied to wastewater treatment.
Multimodal Pressure Sensor: Advancing Continuous Cardiovascular Monitoring through Synergistic Capacitive and Piezoresistive Sensing
Authors: Chowdhury Azmal Huda , Jafarizadeh Borzooye , Pala Nezih , Wang Chunlei
Published: August 2024

Recent advancements in flexible and skin-mountable health monitoring devices have sparked interest in non-invasive methods for continuously capturing subtle human physiological signals. Among these, pressure sensors play a pivotal role, particularly in applications involving pulse detection and electronic skin. While various mechanisms like piezoresistive, capacitive, triboelectric, and piezoelectric sensors have shown promise, their reliance on flexible substrates presents an opportunity to merge different sensing mechanisms into a single, multifaceted sensor, thereby maximizing benefits and mitigating limitations. This study introduces a novel approach by proposing and fabricating a multimodal sensor that seamlessly combines the piezoresistive and capacitive modes of operation. Leveraging finite element analysis, we established design parameters tailored to create a highly sensitive piezoresistive sensor capable of discerning weak arterial pulse waveforms. Simultaneously, for the capacitive sensor aspect, we optimized the performance of a supercapacitive sensor utilizing paper as the sensing layer. This innovative approach in capacitive sensing offers high sensitivity and reliability. The fabrication of both sensors culminated in their integration into a compact, multi-mechanism sensing platform. The resultant multimodal sensor holds promise as a sophisticated, wearable technology for continuous monitoring of cardiovascular pulse waveforms at wrist arterial sites. By synergizing the advantages of capacitive and piezoresistive mechanisms, this innovation paves the way for enhanced accuracy and precision in capturing and analyzing subtle physiological signals.
Effect of Crystal Structure on Dealloying Behavior in PtCo Alloy and Its Impact on the Oxygen Reduction Reaction
Authors: Kim Miseung
Published: August 2024

The proton exchange membrane fuel cell (PEMFC) is considered ideal for power generation due to its high energy conversion efficiency, low operating temperature, and environmentally friendly features. However, the performance of PEMFC is limited by the slow oxygen reduction reaction (ORR) at the cathode, necessitating the use of catalysts such as Pt to enhance the reaction. The Pt catalyst, although effective, poses the challenge of high cost. Consequently, numerous studies have been undertaken to develop more cost-effective catalysts that can match the excellent activity of platinum while maintaining high stability. In particular, the development of alloy nano-catalysts has garnered attention, and promising results have been reported for enhancing catalyst performance through dealloying on the surface of the alloy catalyst. Alloy catalysts prepared by the dealloying method offer the advantage of improving performance by selectively dissolving less-noble metal surfaces and constructing a Pt-rich shell layer.

In this study, we synthesized two PtCo alloy catalysts with distinct crystal structures: face-centered cubic (FCC) and face-centered tetragonal (FCT). To prevent particle growth during the transformation from FCC to FCT when subjected to high-temperature heat treatment for an extended duration, we employed the carbon shell encapsulation technique. Subsequently, the synthesized catalyst underwent acid treatment for dealloying. We investigated the variations in dealloying characteristics based on crystal structures and examined their impact on electrochemical performance.

Various characterizations, including X-ray diffraction (XRD), High-Resolution Transmission Electron Microscopy (HR-TEM), Scanning Electron Microscopy (SEM), Thermo-Gravimetric Analysis (TGA), and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), were conducted to validate the structure of the synthesized PtCo alloy nano-catalyst. Half-cell and unit-cell experiments were carried out to verify electrochemical properties and performance, following the testing protocol suggested by the Department of Energy (DOE) in 2020. Finally, we explored the relationship between the dealloying feature of FCC and FCT and their impact on electrochemical activity and stability.
Effect of Heterojunction Dynamics on Charge Transfer Mechanism in Type-II ZnS/MoS2 Nanocomposite
Authors: Shreya Shreya , Phogat Peeyush , Jha Ranjana , Singh Sukhvir
Published: August 2024

The development of novel nanocomposites holds immense potential for various applications in optoelectronics, catalysis, energy storage systems and photovoltaic applications. In this manuscript, the synthesis and comprehensive characterization of type-II ZnS/MoS2 nanocomposite synthesized by hydrothermal roue are reported. The synthesized nanocomposite was characterized by numerous analytical techniques to analyse its structural, morphological, optical, and electrochemical properties. XRD analysis revealed the presence of both ZnS and MoS2 phases in the nanocomposite, validating its successful formation. UV-visible spectroscopy (UV) was utilized to study its optical properties which revealed a band gap of 3.2 eV. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging demonstrated the presence of large ZnS sheets with smaller nanoparticles of MoS2 dispersed over the surface, indicating the hierarchical structure of the composites. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed to evaluate the electrochemical performance and charge transfer dynamics of the nanocomposite. These techniques facilitated the investigation of their suitability for solar cells. CV analysis displayed prominent reduction peaks, indicating the presence of active electrochemical sites in the nanocomposites. Furthermore, it revealed diffusion-controlled behaviour which indicates the potential of the nanocomposite for efficient solar cells. EIS analysis revealed the presence of Warburg diffusion in the Nyquist plot which indicates the possibility of efficient charge transport and ion diffusion within the nanocomposites. This shows the suitability of nanocomposite material for solar cell applications.
Efficient Direct Recycling of Spent Cathode Materials in Lithium-Ion Batteries
Authors: Ouaneche Tassadit , Stievano Lorenzo , Monconduit Laure , Guery Claude , Sougrati Moulay Tahar , Recham Nadir
Published: August 2024

The demand for lithium-ion batteries (LIBs) has surged in recent years, driven by the rapid growth of electric vehicles (EVs) and emerging energy storage technologies. Yet, this surge in demand has also resulted from a significant increase in the number of spent batteries. Given the potential for environment pollution wastage, it is absolutely crucial to prioritize the recovery and recycling of these used lithium-ion batteries.

The common techniques employed in large-scale industrial settings for battery recycling are pyrometallurgy and hydrometallurgy. These are pivotal multi-step processes, particularly suitable for materials containing Cobalt (Co) and Nickel (Ni), such as NMC (LiNixMnyCozO2). Aside from NMC, there has been a surge in the adoption of LFP (LiFePO4) as a cathode material target for lithium-ion batteries in electric vehicles worldwide over the past few decades. However, these established industrial recycling methods are not applicable to LFP due to the comparatively lower value of iron. This necessitates the pursuit of direct recycling approaches.

In order to accomplish this goal, direct recycling stands out as the most suitable technique for regenerating spent batteries1. Unlike processes involving solution-based or high-temperature steps that entail potentially wasteful steps, this

approach aims to reduce energy consumption and costs, all while maintaining environmental integrity through a judicious utilization of resources, materials, and energy. Consequently, our attention is directed towards this specific LFP material, prompting us to detail a direct recycling procedure for spent LFP cathodes via a chemical lithiation process at room temperature in a solution containing lithium iodide (LiI) and various solvents2 (Fig. 1).

References:

(1) Y. Jin, T. Zhang, M. Zhang, Advances in intelligent regeneration of cathode materials for sustainable lithium-ion batteries, Adv. Energy Mater. 12 (2022), 2201526.

(2) Ouaneche, T. et al. Room temperature efficient regeneration of spent LiFePO4 by direct chemical lithiation. 579, J. Power Sources (2023) 233248.

Figure 1
Optimized Extraction of Mesoporous Nanocomposites from Spent Li-Ion Batteries and Their Use to Construct High-Performance Supercapacitor Devices with Ultra-High Stability
Authors: K. Allam Nageh
Published: August 2024

Lithium-ion batteries (LIBs) are one class of the most significant energy storage devices used nowadays. However, a huge number of spent batteries bring harmful resource waste and environmental hazards as LIBs are mainly composed of heavy metals and organic electrolytes. Consequently, recycling spent LIBs has become a hot topic lately, where researchers are actively working to develop a plethora of methods to extract valuable metals and components. In this study, mesoporous Li–Ni–Mn–Co oxide nanoparticles have been successfully extracted from spent Li-ion batteries using a simple microwave/precipitation method. The as-extracted Li–Ni–Mn–Co oxides were used to construct functional supercapacitor devices. However, the as-extracted oxides showed poor stability and low conductivity. To enhance their cycling stability and conductivity, fullerene (C76) is used as a carbon additive to form Li–Ni–Mn–Co oxide/C76 nanocomposite materials. The morphological, structural, and compositional analyses of those composites were performed using FESEM, HRTEM, XRD, and XPS techniques. The Li–Ni–Mn–Co oxide/C76 nanocomposites exhibit higher conductivity and wettability with an enhanced gravimetric capacitance of ∼357 Fg-1 at 1.0 Ag-1. The asymmetric supercapacitor devices deliver specific energy as high as ∼10 Wh/kg at a specific power of ∼800 W/kg with a superior retention rate of ∼115% after 20,000 cycles with ∼100% Coulombic efficiency.
Electrochemical Extraction of Lib Cathode NMC532 and Its Effects on Inorganic and Organic Acid Extraction Performance
Authors: Watson Bryce , Satterlee Taylor , Schaefbauer Amelia , Carlson Brett , Smirnova Alevtina
Published: August 2024

Environmentally friendly processes to recapture critical metals and supplement domestic markets are vital to overall sustainability in the energy sector. In this work, a new methodology is used to explore electrochemical extraction of critical elements, such as Co and Ni, to compare the extraction performance of hydrochloric acid and acetic acid. The battery cathode material (LiNi0.5Mn0.3Co0.2O2 ) is exposed to acidic solutions at varying experimental parameters, such as concentration, temperature, rotation rate, current density, and hydrogen peroxide content in a rotating disc electrode setup. The concentrations of transition metals are measured over time using inductively coupled plasma mass spectrometry (ICP-MS). These results are compared with simple agitation extraction results under similar conditions without applied current. After electrochemical extraction, the NMC532 residue is collected for morphological analysis using dual beam scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The methodology used can facilitate the development of advanced electrochemical systems and provide valuable insight into key mechanisms for various hydrometallurgical and electrochemical processes.

Acknowledgments

The authors acknowledge financial support from the NSF IUCRC program for the “Center for solid-state electric power storage” (#2052631) and the NSF IUCRC REM program for “Broadening Participation in critical STEM research and innovation through energy sustainability (BP-STEM)” (#2311925). The authors also acknowledge support from the South Dakota Board of Regents for the “Governor’s Research Center (GRC) for electrochemical energy storage”.