bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Three-Dimensional Investigation of the Anodic Catalyst Layer in Polymer Electrolyte Water Electrolysis
Authors: De Angelis Salvatore , Schuler Tobias , Sabharwal Mayank , Holler Mirko , Sicairos Manuel Guizar , Mueller Elisabeth , Buechi Felix N.
Published: July 2022

Reducing precious metal loading in the anodic catalyst layer (CL) is indispensable for lowering capital costs and enabling the widespread adoption of polymer electrolyte water electrolysis (PEWE). This work presents the first three-dimensional reconstruction of a state-of-the-art TiO2-supported IrO2 based core shell catalyst layer (3 mgIrO2/cm2), using high-resolution X-ray ptychographic tomography at a cryogenic temperature of 90 K. The ptychographic tomography was performed at the cSAXS beamline of the Swiss Light Source (PSI). The high data quality and phase sensitivity of the technique have allowed the reconstruction of all four phases namely pore space, IrO2, TiO2 support matrix and the ionomer network, the latter of which has proven to be a challenge in the past. Results show that the IrO2 forms thin nanoporous shells around the TiO2 particles and that the ionomer has a non-uniform thickness and partially covers the catalyst. The TiO2 particles do not form a percolating network while all other phases have high connectivity. The analysis of the CL ionic and electronic conductivity shows that for a dry CL, the ionic conductivity is orders of magnitudes lower than the electronic conductivity. Varying the electronic conductivity of the support phase by simulations reveals that the conductivity of the support does not have a considerable impact on the overall CL electrical conductivity.

Figure 1
High-Pressure PEMWE Stack and System Characterization
Authors: Hancke Ragnhild , Bujlo Piotr , Holm Thomas , Ulleberg Øystein
Published: July 2022

As the urgency to decarbonize the industry and transport sector intensifies, renewable energy-based hydrogen production via advanced low temperature water electrolysis is attracting increased interest. Proton exchange membrane water electrolysers (PEMWE) offer several benefits over the more mature alkaline water electrolysis technology, including its load-following capability and the ability to operate at higher pressures. The latter is important because significant benefits can be harvested by adopting systems operating at pressure-levels compatible with the end use applications and thereby render the mechanical compressor redundant. At IFE we have developed a methodology which encompasses detailed energy- and techno-economic calculations of high-pressure systems, and a comparison between high-pressure electrolysis and state-of-the-art electrolysis at 30 bar in combination with a compressor has been carried out. Here, direct pressurization to 80 and 200 bar (relevant for, e.g., methanol and ammonia production) was found to be economically viable.

To realize high-pressure H2 generation systems, many challenges related to system operability, efficiency and safety needs to be addressed. As part of the national infrastructure “The Norwegian Fuel Cell and Hydrogen Centre”, Institute for Energy Technology (IFE) has installed a flexible PEM water electrolyzer system platform for testing of small-scale prototype electrolyzers up to 33 kW and 200 bar differential pressure. The test rig is integrated with a sophisticated power conditioning system which consists of three custom-built DC/DC-converters (for PEMWE, PEMFC, and Li-ion battery systems), all coupled to the same DC-bus. This configuration makes it possible to test different hybrid electric topologies and to emulate different loads (e.g., grid load profiles, wind generation). This one-of-a-kind high-pressure PEMWE test facility at IFE is well suited to study performances of next-generation PEMWE stacks and systems, and to tailor and test control strategies that safeguards the system and maximizes efficiency and durability

The test rig has been commissioned with a prototype high-pressure stack with a production capacity of 2 Nm3/h (Nel Hydrogen), and the identified economically viable pressure range of 80-200 bar has been the main target for an experimental test campaign. The experimental results are presented from stack testing including polarization curves and EIS data as a function of temperature, pressure and current density. The results are discussed in relation to the techno-economic model, in order to identify pathways towards more efficient hydrogen production.

Figure 1
Understanding Proton Exchange Membrane Water Electrolyzer Hydrogen Crossover Mitigation in Reactive Spray Deposition Technology Fabricated Dual Recombination Layers through Distribution of Relaxation Times Analysis
Authors: Gado Alanna M. , Ouimet Ryan J. , Bliznakov Stoyan , Bonville Leonard J. , Maric Radenka
Published: July 2022

Proton exchange membrane water electrolyzers (PEMWEs) are a promising technology to produce zero-carbon emission, renewable, high-purity hydrogen. [1] There is a need to reduce capital cost while improving performance for the progression of widespread development. The crossover of hydrogen from the cathode into the anode not only restricts cell performance, but also poses a safety hazard, as the crossover reaches the lower explosive limit of hydrogen in oxygen. [2] Previous work has been conducted on the fabrication and testing of Pt recombination layers in PEMWEs. The addition of the Pt recombination layer has proven to be an effective mitigation strategy for hydrogen crossover while improving performance. [3, 4] Further investigation is needed to understand the mechanisms of the Pt recombination layer.

In this work, reactive spray deposition technology (RSDT) was used to deposit two Pt recombination layers separated by a membrane. Testing of a single cell 25 cm2 PEMWE was conducted. Polarization analysis, electrochemical impedance spectroscopy, and distribution of relaxation times were used to investigate the cell performance. Results show good cell performance and hydrogen crossover reduction, as well as insight to the mechanisms of the chemical reactions that occur on the dual recombination layer.

References

[1] Aricò, A. S., Siracusano, S., Briguglio, N., Baglio, V., Di Blasi, A., & Antonucci, V. (2012). Polymer electrolyte membrane water electrolysis: Status of technologies and potential applications in combination with renewable power sources. Journal of Applied Electrochemistry, 43(2), 107–118. https://doi.org/10.1007/s10800-012-0490-5

[2] Schalenbach, M., Carmo, M., Fritz, D, L., Mergel, J., Stolten, D. Pressurized PEM water electrolysis: Efficiency and gas crossover, International Journal of Hydrogen Energy, 38(35), (2013), 14921-14933.

[3] Klose, C., Trinke, P., Bohm, T., Bensmann, B., Vierrath, S., Hanke-Rauschenbach, R., Thiele, S. Membrane Interlayer with Pt Recombination Particles for Reduction of the Anodic Hydrogen Content in PEM Water Electrolysis, Journal of Electrochemical Society, 165(16), (2018), F1271-F1277.

[4] Mirshekari, G., Ouimet, R., Zeng, Z., Yu, H., Bliznakov, S., Bonville, L., Niedzwiecki, A., Capuano, C., Ayers, K., Maric, R. High-performance and cost-effective membrane electrode assemblies for advanced proton exchange membrane water electrolyzers: Long-term durability assessment. International Journal of Hydrogen Energy, Volume 46, Issue 2, 2021, Pages 1526-1539, ISSN 0360-3199, https://doi.org/10.1016/j.ijhydene.2020.10.112.
Selective Electrochemical CO2 Reduction to Formate over Bismuth Nanosheets Derived By in-Situ Morphology Transformation of Bismuth Oxides
Authors: Lee Jungkuk , Liu Hengzhou , Chen Yifu , Li Wenzhen
Published: July 2022

The electrochemical CO2 reduction reaction (CO2RR) has attracted enormous attention as a promising technology not only to mitigate CO2 accumulation, but also to convert CO2 into valuable chemicals and fuels.Formate/formic acid is a value-added product from CO2RR that is an important intermediate for chemical industries such as medicines, rubbers, leather and deicing materials. Moreover, it can be used as a source for hydrogen storage, transportation, as well as a fuel for direct formic acid fuel cells. Bismuth nanosheets (BiNSs) have been recognized as a promising catalyst for electrochemical CO2 reduction (CO2RR) to formate, but its preparation typically involves an elaborate synthesis of Bi-precursors under elevated temperature and pressure. Here, we have demonstrated a simple, low-cost preparation method for BiNSs by in-situ morphology transformation of Bi2O3 particles by simple electrochemical processing. SEM analysis showed that such transformation is exceedingly facile on the precipitated Bi2O3 particles compared to BiNPs and Oxi-BiNPs, revealing the crucial roles of oxygen and the initial morphology of Bi precursor in the exfoliation of BiNSs. The OD-BiNS exhibited superior CO2RR performance compared to the BiNPs and Oxi-BiNPs. 93% of FE was achieved with the current density of 62 mA cm−2 at −0.95 VRHE in the H-type cell. The enhanced CO2RR performance of OD-BiNSs can be attributed to its higher intrinsic activity and increased ECSA. 94% of FE with a high current density of 200 mA cm−2 was achieved in the flow cell, suggesting OD-BiNSs as a promising catalyst for practical applications of CO2RR. Our recent research on flow electrolytic cells for CO2 reduction will also be presented.
(Invited) Electrochemical Pumping for Hydrogen Storage and Distribution in the Natural Gas Pipeline
Authors: Arges Christopher G. , Venugopalan Gokul , Bhattacharya Deepra
Published: July 2022

Over the next decade, the production and use of hydrogen in various sectors of the global economy is anticipated to grow significantly. It is an already important feedstock in the production of ammonia and desulfurization of fuels in addition to being used in metals refining and as a coolant in thermal electric power plants. More recently, hydrogen is being considered for long-term seasonal energy storage for energy derived from renewables like solar and wind. To alleviate the severe costs of building out completely new infrastructure, the U.S. natural gas pipeline represents an enticing proposition for hydrogen storage and a potential distribution network from centralized production facilities. Embrittlement concerns of the pipeline with hydrogen limit the hydrogen partial pressure/concentration of hydrogen to be stored. Because many end use applications often require high purity hydrogen, it is necessary to separate/de-blend hydrogen from natural gas and compress it at the point-of-use.

This talk presents high-temperature polymer electrolyte membrane (HT-PEM) electrochemical hydrogen pumps for separating hydrogen from gas mixtures. Hydrogen purification to +99% from syngas (25mol% hydrogen and 40mol% carbon monoxide (CO)) at 1 A cm-2 and cell voltage of 0.4 V with an electrochemical hydrogen pump was demonstrated. About 90% of hydrogen used in the United States today derives from steam-reformed natural gas that contains large concentrations of CO – which is a potent platinum electrocatalyst poison at temperatures below 100 °C. The hydrogen purification from syngas was possible with an electrochemical hydrogen pump operated at 220 °C and by using: i.) an ion pair HT-PEM that exploits electrostatic interactions to prevent phosphoric acid leaching at elevated temperatures from the membrane matrix and in the presence of water and ii.) a phosphonic acid ionomer electrode binder. The membrane electrode assembly (MEA) with the said materials and platinum on carbon (Pt/C) electrocatalyst was also effective for purifying hydrogen from other types of reformed hydrocarbons with different CO and hydrogen concentrations. Unexpectedly, operating the HT-PEM hydrogen pump at 220 °C minimized CO impact on cell polarization. At this temperature, cell polarization was governed by the hydrogen concentration in the gas feed. These observations motivate future work to develop new electrodes and electrode binders that can extract, purify, and compress hydrogen with feed streams that have low hydrogen content and contain other constituents in natural gas (methane, ethane, t-butyl mercaptan, etc).
CuBi2O4 Based Hybrid Photocathodes for Enhancement of the Photoelectrochemical Reduction of CO2
Authors: Yoon Jihyun , Lee Sanwoo , Choi Taekjib
Published: July 2022

Photoelectrochemical (PEC) CO2 reduction reaction (CO2RR) is a promising strategy to mitigate energy shortage and global warming by conversion of CO2 into chemical fuels. CuBi2O4 (CBO) is an attractive p-type photoelectrode, because it has a suitable band gap (1.5 to 1.8 eV) for visible light absorption and band edge position for PEC CO2RR. Furthermore, Cu-based catalysts can convert CO2 into multi-carbon products. However, the photoconversion efficiency of CBO is limited by short carrier diffusion length and poor photostability. In this work, we fabricated hydrothermal CBO based hybrid photocathode. The hydrothermal CBO/cellulose nano fibers (CNFs) composites with a large surface area and a porous network structure were prepared to achieve higher photocurrent density, in which CNFs are an abundant, non-toxic, and eco-friendly polymer, offering a porous and flexible network structure as a template during hydrothermal treatment. To enhance the PEC CO2RR, we introduce the ultrathin TiO2 a passivation layer deposited by atomic layer deposition (ALD) and NiO as a hole transport layer (HTL) to increase charge transport efficiency. Therefore, we will discuss enhanced performance and stability by introducing these improvement methods.
Low-Loading Platinum Alloy Electrocatalyst Supported on Hollow Carbon for the Four-Electron Oxygen Reduction Reaction
Authors: Yim Kyungmin , Youngbin Lee , Kim Jinsoo
Published: July 2022

The oxygen reduction reaction (ORR) at the cathode of proton exchange membrane fuel cell is a very slow reaction. Therefore, Pt-based catalyst is only applied to practical application. Since Pt-based noble metals are very expensive, research is underway to reduce the amount of noble metals or to replace Pt-based noble catalysts. To reduce the total production cost of fuel cells, it is required to develop a simple fabrication process with mass-productivity as well as to reduce the use of noble metals. Metal-organic framework (MOFs)-derived catalyst has been investigated as ORR catalyst due to its significantly large surface area and open pore structure. MOFs-based electrocatalyst still showed low catalytic activity and stability compared to commercial platinum based catalyst. To solve this problem, a small amount of precious metal has been added to the MOFs to maximize the performance of the MOF-based electrocatalyst. In this study, we synthesized ultra-low loading Pt@Co-NC electrocatalyst supported on MOF-derived hollow carbon. Hollow carbon was prepared by carbonization of MOF@MOF core-shell structure. After carbonization, platinum is loaded by polyol method and finally PtCo-N-C electrocatalyst was successfully synthesized through annealing process. Synthesized PtCo-N-C catalysts showed high ORR performance and four-electron selectivity in acidic condition.
Biobased Polymer Synthesis from Vanillin in an Electrochemical Flow Reactor
Authors: Kunkel Robin , Fath Maximilian , Schmiedl Detlef , Müller Dominik , Simmat Fabian , Schmidt Volkmar M , Tübke Jens
Published: July 2022

The development of new synthesis routes for the production of biobased polymers is an urgent matter in the context of climate change. One possible promising key intermediate is vanillin (4-hydroxy-3-methoxybenzaldehyde), as it is one of a few aromatic biobased compounds, which is already available on an industrial scale. Vanillin can be produced sustainably with potential yields of up to 7% from lignin, a side product in the paper and pulp industry with amounts of over 107 tons per year. Therefore, much effort was spent from the scientific community for the preparation of a broad range of new vanillin-based polymers [1].

One attractive synthesis route is the electrochemical reductive production of polyvanillin, a total vanillin-based polymer. Polyvanillin is synthesized by electrochemical pinacolization of divanillin (5-5´bisvanillyl), which is easily available by enzymatic conversion of vanillin with horseradish peroxidase and hydrogen peroxide (Scheme 1). Recent studies from others [2] as well as from our working group [3] showed the feasibility of this synthesis route and investigated the impact of electrochemical reaction parameters in batch cells.

As a next step, we here transferred the electrochemical reduction of divanillin to polyvanillin from an electrochemical batch reactor into a divided plan parallel flow reactor in recycle mode. The reductive conversion of the aldehyde groups was monitored by an on-line UV-Vis setup and the molecular weight increase was followed by size exclusion chromatography. Further, 2D-NMR (HSQC, 1H/13C) was used to identify structural features of the produced polyvanillin samples. The impacts of different electrochemical impact parameters, such as applied charge, current density, flow velocity and concentration were investigated. Current densities of over 50 mA cm-2 were readily achievable and weight-averaged molecular weights up to 4300 g mol-1 were reached.

This study shows an innovative electrochemical approach for the synthesis of new biobased polymers in an electrochemical flow reactor offering a total green process.

References

[1] M. Fache, B. Boutevin, S. Caillol, Eur. Polym. J. 2015, 68, 488-502.

[2] A. S. Amarasekara, B. Wiredu, A. Razzaq, Green Chem.
2012, 14, 2395–2397.

[3] R. Kunkel, V.M. Schmidt, C. Cremers, D. Müller, D. Schmiedl, J. Tübke, RSC Adv.
2021, 11, 8970-8985.

Figure 1
(Digital Presentation) Electrochemical Synthesis of C-Azanucleosides Based on Structural Analysis for in Situ Generated Intermediates
Authors: Morizumi Haruka , Okamoto Kazuhiro , Kitano Yoshikazu , Okada Yohei , Chiba Kazuhiro
Published: July 2022

Redox-induced regioselective C(sp3)-H C-glycosidation for unactivated prolinols was achieved by controlling the anomeric reactivity of electrochemically generated iminium cations. A mechanistic study revealed that the intermediate was pooled as covalent azaribose or iminium cation species in situ, and the electrophilicity of intermediates can be adjusted by changing coexisting acids. We found that the armed/disarmed analogy concept of traditional glycochemistry can be adapted to our C-glycosidation reaction. Finally, we invented a logical synthetic methodology, named “reactivity switching” concept, and synthesized a series of C-azanucleosides based on this methodology.

Figure 1
(Digital Presentation) Electrochemical Peptide Synthesis Utilizing Triphenylphosphine (Ph3P) in a Biphasic System
Authors: Nagahara Shingo , Okada Yohei , Kitano Yoshikazu , Chiba Kazuhiro
Published: July 2022

Recently, peptides have been recognized as candidates for medium molecular medicines, which refers to pharmaceutical compounds whose molecular weights are roughly in the 1000 to 5000 range. This class of medicines has more specificity and fewer side effects than conventional small molecular medicines. However, an amount of waste derived from coupling reagents is regarded as a serious drawback of peptide synthesis from a green chemistry viewpoint.1

To address this issue, we have developed an electrochemical peptide synthesis utilizing triphenylphosphine (Ph3P) in a biphasic system (MeCN-c-Hex).2 Anodic oxidation of Ph3P generates a phosphine radical cation, which serves as the coupling reagent to activate carboxylic acids followed by peptide bond formation and production of triphenylphosphine oxide (Ph3PO) as a stoichiometric byproduct.3 Given that methods to reduce Ph3PO to Ph3P have been reported,4 Ph3P can be a recyclable byproduct unlike byproducts from typical coupling reagents.

In the optimized condition, we found that all canonical amino acids can be applied to electrochemical peptide bond formation and succeeded in the selective recovery of desired peptides and Ph3PO in combination with a soluble tag-assisted liquid-phase peptide synthesis. Moreover, a commercial peptide active pharmaceutical ingredient (API), leuprorelin, was successfully synthesized without the use of traditional coupling reagents.

Reference

1. M. C. Bryan, P. J. Dunn, D. Entwistle, F. Gallou, S. G. Koenig, J. D. Hayler, M. R. Hickey, S. Hughes, M. E. Kopach, G. Moine, P. Richardson, F. Roschangar, A. Steven and F. J. Weiberth, Green Chem., 2018, 20, 5082–5103.

2. S. Nagahara, Y. Okada, Y. Kitano, K. Chiba, Chem. Sci., 2021, 12, 12911–12917.

3. A. Palma, J. Cardenas and B. A. Frontana-Uribe, Green Chem., 2009, 11, 283–293.

4. D. Hérault, D. H. Nguyen, D. Nuel and G. Buono, Chem. Soc. Rev., 2015, 44, 2508–2528.

Figure 1
(Digital Presentation) Electrochemical Phosphonylation of π-Conjugated Polymers
Authors: Taniguchi Kohei , Kurioka Tomoyuki , Shida Naoki , Tomita Ikuyoshi , Inagi Shinsuke
Published: July 2022

π-Conjugated polymers exhibit attractive optoelectronic properties because of their extended π-conjugation system along with main chains. Therefore, the introduction of functional groups into their main chains is a straightforward strategy to control their optoelectronic properties. In this context, post-functionalization is a practical methodology to install functional units. Among the post-functionalization methods, electrochemical post-functionalization is a promising fashion due to its outstanding abilities to transform aromatic C–H bonds of π-conjugated polymers into various functional units.1) For example, anodic chlorination of poly(3-hexylthiophene) (P3HT) has been reported (Fig. 1 (a)).2) However, functional groups available for this post-functionalization remain limited to those derived from nucleophilic dopants such as a chloride ion.

Here, to expand the applicable functional groups for electrochemical post-functionalization, we attempted to develop the electrochemical phosphonylation of P3HT and poly(9,9-dioctylfluorene) (PFO) (Fig. 1 (b)). With the use of non-nucleophilic dopants and triethyl phosphite as neutral nucleophiles, we successfully achieved C–H phosphonylation of the main chains of these polymers. The introduced phosphonyl groups significantly affected the optoelectronic properties of P3HT and PFO. Particularly, phosphonylated PFO was found to show unique emitting properties.

References

1) S. Inagi, T. Fuchigami, Macromol. Rapid Commun., 2014, 35, 854.

2) S. Hayashi, S. Inagi, K. Hosaka, T. Fuchigami, Synth. Met., 2009, 159, 1792.

Figure 1
Engineering Extracellular Electron Transfer in
Escherichia coli
for Microbial Electrochemical Devices
Authors: Mouhib Mohammed , Reggente Melania , Li Lin , Schuergers Nils , Boghossian Ardemis Anoush
Published: July 2022

Microbes hold great potential for green electrochemical synthesis as well as bio-electricity generation from organic waste. The key to the successful development of microbial electrochemical devices lies with the ability of the microbes to transport electrons across their outer membranes. These devices thus often rely on the use of microbes known as exoelectrogens, which include bacteria that have evolved metabolic pathways that enable extracellular electron transfer (EET) to solid substrates for cellular respiration. While exoelectrogens demonstrate facilitated electron transfer with the electrodes of these devices, natural exoelectrogens are often restricted to utilizing a narrow range of substrates that limits their versatility for processing different organic wastes and electrosynthesizing a rich diversity of high-value chemicals. By contrast, non-exoelectrogenic microbes such as
Escherichia coli
that lack efficient EET pathways are host to rich metabolic reaction networks that can be more readily tailored for various applications using synthetic biology.

In this work, we biologically engineer
E. coli
for enhanced EET. To this end, we expressed different combinations of proteins from the natural exoelectrogen
S. oneidensis
MR-1, as well as
E. coli
native proteins to optimize EET of the bioengineered strain. The bioengineered strains show significant improvements in electron transfer rates, as confirmed through colorimetric reduction assays of soluble electron acceptors and electrochemical characterizations following electrode reduction. The improved EET demonstrated in this work paves the way for increasing the efficiency of existing
E.

c

oli

-
based electrochemical devices while opening the doors to new applications that benefit from the broad chemical repertoire of these microbes.
A High-Throughput Strategy for Glycine Oxidase Biosensor Development Reveals Glycine Release from Cultured Cells
Authors: Mauzeroll Janine
Published: July 2022

Glycine is an important biomarker in clinical analysis due to its involvement in multiple physiological processes. As such, the need for low-cost analytical tools for glycine detection is growing. As a neurotransmitter, glycine is involved in inhibitory and excitatory neurochemical transmission in the central nervous system. In this work, we present a 10 μM Pt-based electrochemical enzymatic biosensor for localized real time measurements of glycine. This biosensor relies on amperometric readout and does not require additional redox mediators. The biosensor was characterized and applied for real-time glycine detection from cells, mainly HEK 293 cells and primary rat astrocytes. Taken together, this study demonstrates a glycine oxidase based biosensor useful for extracting pertinent information about glycine levels in a wide range of biological contexts.
(Invited) Electrochemical Detection of Pseudomonas Aeruginosa Quorum Sensing Molecules at Micro Liquid|Liquid Interface Via Facilitated Proton Transfer Mechanism
Authors: Stockmann Talia Jane , Moshrefi Reza
Published: July 2022

The micro interface between two electrolyte solutions (micro-ITIES) has been exploited as a miniaturized electrochemical platform for detection of Pseudomonas aeruginosa. Electrochemical detection methods for point-of-care-devices in healthcare environments are ideal owing to their small equipment footprint and relative ease of use, while simultaneously, disposable electrode materials are easily fabricated. Meanwhile, P. aeruginosa is a pathogenic bacteria that poses a serious health risk to patients with compromised immune systems. Herein, a proof-of-concept electrochemical method is demonstrated that employs a micro-ITIES between water and oil (w/o) held at the tip of a glass capillary which targets two quorum sensing (QS) molecules produced throughout the bacteria’s life-cycle: 4‐hydroxy‐2‐heptylquinoline (HHQ) and 2‐heptyl‐3,4‐dihydroxyquinoline (PQS, Pseudomonas quinolone signal). QS molecules are used to signal colony growth in a pseudo-multicellular fashion; however, HHQ and PQS are also known virulence factors and are unique to this form of pathogenic bacteria. HHQ and PQS show excellent solubility in chlorinated organic solvent with limited partitioning to the aqueous phase. Moreover, as observed electrochemically, they facilitate proton transfer across the w/o interface which can be monitored/quantified and is exploited here as a means for early bacterial detection. This work demonstrates that the micro-ITIES can serve as a viable platform for P. aeruginosa identification and quantification. Density functional theory calculations were also performed to determine the proton affinities and gas-phase basicities of HHQ/PQS, as well as elucidate the likely site of stepwise protonation within each molecule.

Figure 1
Electrochemically-Driven Secondary Folding and Assembly of Peptides and Proteins
Authors: Masquelier Eloise , Liang Sheng-Ping , Levenson Robert , Malady Brandon , Sepunaru Lior , Morse Daniel , Gordon Michael
Published: July 2022

Reversible electrochemical triggering of the random coil to α-helix conformational transition of polylysine, and secondary folding of reflectin A1, was accomplished at a Pt electrode at potentials < |1| V vs. Ag/AgCl. Direct electroreduction of the N-terminus vs. ε-amino groups in lysine (Lys) sidechains, imidazolium groups of histidine-containing reflectin A1, as well as hydronium reduction and electrolysis, could be easily distinguished and deconvolved using differential pulse voltammetry. Electrochemistry was coupled with in situ UV absorbance, circular dichroism, and dynamic light scattering to dynamically follow the evolution of secondary folding and assembly of polylysine and reflectin at different potentials. Isotope experiments in H2O vs. D2O unequivocally confirm that direct electroreduction of ε-NH3
+/ND3
+ groups in Lys sidechains, rather than electrochemically generated pH gradient-induced deprotonation, leads to subsequent α-helix formation in polylysine. The site-selective electrochemistry and optical methodologies to be presented herein can be generalized and extended to interrogate other protonation-sensitive biomolecular systems, and potentially provide access to early intermediates and control over the dynamic structural evolution of peptides and proteins.

[1] E. Masquelier, S.P. Liang, L. Sepunaru, D. E. Morse, M. J. Gordon, "Reversible Electrochemical Triggering and Optical Interrogation of Polylysine α-helix formation " Bioelectrochemistry vol. 144, p. 108007, 04/2020 2022, doi: 10.1016/j.bioelechem.2021.108007

[2] S. P. Liang, R. Levenson, B. Malady, M. J. Gordon, D. E. Morse, and L. Sepunaru, "Electrochemistry as a surrogate for protein phosphorylation: voltage-controlled assembly of reflectin A1," J R Soc Interface, vol. 17, no. 173, Dec 23 2020, doi: 10.1098/rsif.2020.0774.
Electrochemical Determination of Deoxynivalenol Using a Modified Glassy Carbon Electrode
Authors: Arteshi Kojabad Yaser , Lima Dhésmon , Mendes Hacke Ana Carolina , Kuss Sabine
Published: July 2022

Mycotoxins are toxic secondary metabolites, produced by different types of molds. These substances cause economic losses and are considered as a global public health concern because the food supplies that are contaminated by mycotoxins are graded as unfit for consumption.1 Deoxynivalenol (DON), also called vomitoxin is one of the most representative mycotoxins which is mainly produced by Fusarium graminearum and Fusarium culmorum. DON commonly contaminates grains, such as corn, wheat and rice. DON has also been found to contribute to chronic disease development.2 The DON analysis for quality control purposes in grains commonly relies on expensive methods, such as GC-MS and HPLC or complex biosensors.3 These methods are used because of high sensitivity which makes it possible to detect trace amounts of DON in complex media. In this work, we propose an easy to use, rapid and cost-efficient detection method for DON based on modified glassy carbon electrodes (GCE). The electrochemical behavior of DON is studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. Limits of detection and quantification are determined. The performance of the sensor in spiked solutions and real samples is studied and compared with standard methods.

References

(1) Lee, H. J.; Ryu, D. Journal of Agricultural and Food Chemistry
2017, 65, 7034-7051.

(2) Pestka, J. J.; Smolinski, A. T. Journal of Toxicology and Environmental Health, Part B
2005, 8, 39-69.

(3) Tittlemier, S. A.; Brunkhorst, J.; Cramer, B.; DeRosa, M. C.; Lattanzio, V. M. T.; Malone, R.; Maragos, C.; Stranska, M.; Sumarah, M. W. World Mycotoxin Journal
2021, 14, 3-26.
Improving Lithium Storage Properties of SiOx Nanosheets By Introducing MoO2 Nanoparticles
Authors: Lee Tae Rim , Kim Soohwan , Yoo Hyundong , Kim Hansu
Published: July 2022

Silicon oxides (SiOx) have been recognized as promising candidates to replace commercial graphite anode materials in lithium-ion batteries. Two-dimensional (2D) microstructure of SiOx nanosheets leads to high capacity retention with the excellent dimensional stability. However, they have the disadvantage of having low specific capacity and low initial Coulombic efficiency. Here, molybdenum dioxide (MoO2) nanoparticles were introduced to compensate for the shortcomings of SiOx nanosheets. MoO2 nanoparticles are chemically bonded to the surface of SiOx nanosheets by Mo-O-Si bond, as a result, showing the improved reversible capacity and initial Coulombic efficiency while maintaining the strength of SiOx nanosheets. The observed improvement can be explained by the synergistic effect resulted by the combination of SiOx nanosheets with zero-dimensional (0D) MoO2 nanoparticles. The former provides favorable microstructures and dimensional stability while the latter offers abnormal lithium storage sites and highly reversible phase transition. In the presentation, the improved lithium storage properties of 2D-SiOx/0D-MoO2 nanocomposites will be discussed in detail.
(Invited) Improved Thermal Stability of Low-Probe Density DNA SAMs Prepared with Electrodeposition
Authors: Ma Tianxiao , Ma Tianxiao
Published: July 2022

DNA self-assembled monolayer (SAM) on gold electrodes has been widely used for biosensing.1, 2 The sensor stability and performance determine the reliability of the test results in early disease detection and point-of-care use.3, 4 We have carefully examined the thermal stability of a mixed SAMs composed of a short alkylthiol and alkylthiol modified DNA prepared with electrodeposition vs. those prepared at OCP (Open Circuit Potential) on a single crystal gold bead electrode. The nature of these two types of SAMs were carefully studied in buffer after exposure to different temperatures using in-situ fluorescence microscopy and electrochemical measurements. The analysis showed that surfaces with hexagonal symmetry were thermally less stable than those with rectangular or square symmetry, suggesting that the crystallography of the gold substrate plays an important role in sensor stability and performance in addition to the DNA density.5

We also found that OCP deposition creates a surface with high DNA coverage (>1012 DNA/cm2) but with higher level of irreproducibility. Even though this kind of surface can be more thermally stable, it is not optimal for effective biosensing due to its high coverage.6 It also seems to be challenging to make DNA SAMs with both low coverage and high thermal stability by using current SAM preparation protocols (e.g., OCP). In this study, we show that electrodeposition can prepare DNA SAMs with both higher thermal stability than those made at OCP and with good control of low surface coverage. This study provides valuable insights on making high quality DNA SAMs with better stability and functionality and improved reproducibility.

References:

Brittain, W. J.; Brandsetter, T.; Prucker, O.; Rühe, J. ACS Appl. Mater. Interfaces
2019, 11, 39397–39409.

Civit, L.; Fragoso, A.; O’Sullivan, C. K. commun. 2010, 12, 1045–1048.

Sheridan, C. Biotechnol. 2020.

Panjan, P.; Virtanen, V.; Sesay, A. M. Talanta
2017, 170, 331–336.

Ma, Tianxiao; Dan Bizzotto. Analytical Chemistry. 2021. 93 (48), 15973–15981.

Peterson, A. W.; Heaton, R. J.; Georgiadis, R. M. Nucleic Acids Res. 2001, 29, 5163–5168.

Figure 1
Biomimetic Supported Lipid Bilayer on Thylakoid Membrane-Based Photobioelectrochemical System for Stability Enhancement
Authors: Yun JaeHyoung , Kim Seon Il , Ryu Wonhyoung
Published: July 2022

Light-induced charge separation in photosynthetic reaction centers has a very high quantum yield. Due to this high quantum yield, bioenergy harvesting using photosynthesis of plant has been studied extensively. In the studies using algal cells or chloroplasts, their lipid membranes interfere with electron extraction. Therefore, most of studies are underway by using extracted photosynthetic organelles such as photosystems (PS I, II) and thylakoid membranes (TMs). However, without lipid membrane, the stability of photosynthetic organelles cannot be maintained. This is because photosynthesis generates reactive oxygen species (ROS) and protons that cause the degradation of photosynthetic organelles along with the production of high-energy electrons. On the other hand, chloroplasts have the internal environment separated by the lipid membrane to maintain homeostasis, which controls the level of ROS and pH within the chloroplasts.

In this study, by mimicking chloroplast, we propose to form a biomimetic supported lipid bilayer (SLB) to maintain stability while constructing a TM-based photobioelectrochemical system. Alginate was used as a synthetic extracellular matrix (ECM), and SLB was formed with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) through vesicle fusion. The swelling of the alginate prevents direct contact of TM-alginate composite film with the electrode and prevents separation of inside of the biomimetic protochloroplast from outside environment. To solve this problem, crosslink alginate with CaCl2 water solutions containing 20% ethanol to prevent warping of composite film and amino groups were created through silanization on ITO electrode to improve adhesion with film. Thereafter, SLB formation conditions were analyzed through confocal microscopy. With the formed DOPC SLB, it was verified by the dye release test whether the inside of protochloroplast was separated from the outside environment. Under the SLB-encapsulating environment, pH and ROS were controlled by ADP, ascorbate and glutathione. To confirm the improvement of the stability of TM, the long-term photocurrent was measured in the presence or absence of SLB and stability-maintaining materials. Moreover, SLB can act as a separator in electrochemical circuits due to its high electrical resistance. Electrical insulation property of SLB was confirmed using electrochemical impedance spectroscopy (EIS).

References

[1] Kosumi, Daisuke, et al. Journal of Photochemistry and Photobiology A: Chemistry
358 (2018): 374-378.

[2] Pankratov, Dmitry, Galina Pankratova, and Lo Gorton. Current Opinion in Electrochemistry
19 (2020): 49-54.

[3] Kluzek, Monika, et al. Soft matter
14.28 (2018): 5800-5810.

[4] Blokhina, Olga, Eija Virolainen, and Kurt V. Fagerstedt. Annals of botany
91.2 (2003): 179-194.

[5] Vockenroth, Inga K., et al. Biointerphases
3.2 (2008): FA68-FA73.
Autonomous Image Analysis to Accelerate the Discovery and Integration of Energy Materials
Authors: Eslamibidgoli Mohammad J. , Malek Kourosh , Eikerling Michael
Published: July 2022

Accelerating the development of electrochemical energy devices (e.g., batteries, fuel cells, electrolysis cells) is pivotal for the transition towards a green and sustainable energy economy. A significant proportion of development efforts in this realm is relying on new functional materials as electrocatalytically active media, ionic media, porous transport media, or multi-functional electrodes. Experimental materials research harnesses a broad spectrum of imaging and visualization methods, based on modern spectroscopy, microscopy, and scattering techniques. These techniques are utilized to quantify structural characteristics of materials and to detect and monitor structural changes during fabrication and normal operating cycles of the device. The extreme diversity and the complexity of materials leave the applications of conventional methods for image processing often empirical and indiscriminate. Recently, deep learning (DL) models based on deep convolutional neural networks (ConvNets) have been transforming the field of computer vision by outperforming the classical algorithms in various problems such as image recognition, reconstruction, synthesis, style transfer, and other tasks. To leverage the advancements in DL-based approaches in materials research, ConvNet models are employed for various analysis tasks like segmentation, object detection, denoising, or super-resolution microscopy. Here, we will present DL-based methodical pipelines to automate the particle size distribution analysis of Pt nanoparticles in catalyst layers [1] and for high-throughput screening of catalyst layer inks [2] in polymer electrolyte fuel cells.

References:

[1] Colliard-Granero, André, Mariah Batool, Jasna Jankovic, Jenia Jitsev, Michael Eikerling, Kourosh Malek, and Mohammad Javad Eslamibidgoli. "Deep learning for the automation of particle analysis in catalyst layers for polymer electrolyte fuel cells." Nanoscale (2021) DOI: 10.1039/d1nr06435e

[2] Eslamibidgoli, Mohammad J., Fabian P. Tipp, Jenia Jitsev, Jasna Jankovic, Michael H. Eikerling, and Kourosh Malek. "Convolutional neural networks for high throughput screening of catalyst layer inks for polymer electrolyte fuel cells." RSC Advances 11, no. 51 (2021): 32126-32134.
(Digital Presentation) Bioelectrochemistry of Neuronal Tau Protein
Authors: Martic Sanela
Published: July 2022

Tau is a neuronal protein and one of the biomarkers of neurodegenerative diseases, such as Alzheimer’s disease. Tau protein undergoes post-translational modifications, aggregation, and is a viable drug target. In addition, this protein is a vital biomarker in biological fluids towards early detection of neurodegenerative diseases. We reported on using electrochemical impedance spectroscopy and cyclic voltammetry for detection of protein-protein interactions (1), protein-ligand interactions (2), enzymatic catalysis and enzyme inhibition (3) while focusing on tau protein and its biochemistry. For example, tau-tau, tau-ferritin, tau-transferrin protein interactions were monitored, and protein kinase-catalyzed phosphorylation of tau protein was detected. The phosphorylation inhibitors, such as antibodies, were screened for their efficacy. Bioelectrochemical methodologies were used to gain insight into various facets of protein biochemistry, and represent promising tools in neuroscience research.

References

A) Carlin, N., Martic-Milne, S. (2018). Anti-tau antibodies based electrochemical sensor for detection of tau protein. J. Electrochem. Soc.165: G3018-G3025. B) Jahshan, A., Esteves, J.O.V., Martic-Milne, S. (2016). Evaluation of ferritin and transferrin binding to tau protein. J. Inorg. Biochem. 162: 127-134. C) Esteves, J.O.V., Trzeciakiewicz, H., Loeffler, D.A., Martic, S. (2015). Effects of tau domain-specific antibodies and intravenous immunoglobulin on tau aggregation and aggregate degradation. Biochemistry. 54: 15-18.

Trzeciakiewicz, H., Esteves, J.O.V., Carlin, N., Martic, S. (2015). Electrochemistry of heparin binding to tau protein on Au surfaces. Electrochim. Acta. 162: 24-30,

Esteves, J.O.V., Martic-Milne, S. (2016). Electrochemical detection of anti-tau antibodies binding to tau protein and inhibition of GSK-3-β-catalyzed phosphorylation. Anal. Biochem. 496: 55-62
Volume Change Behavior of Graphite Electrode for Lithium-Ion Battery By in Situ Electrochemical Dilatometry
Authors: LIM Gayoung , Park You Kyung , Park Hyeong-Il , Kim Hansu
Published: July 2022

Graphite undergoes volume expansion and contraction upon lithium ion intercalation and deintercalation process, which affect the internal microstructure of graphite electrode during cycling. In this work, the expansion and contraction in graphite electrode was investigated using in situ electrochemical dilatometry to determine which factor affect the volume change behavior. It was found that the thickness change of the graphite electrode was highly correlated with the microstructure of graphite electrode, such as the preferential orientation of graphite particles, pore structure of graphite electrodes. It was also found that the differential expansion plots of graphite electrodes provides more detailed information on the expansion and contraction behavior of Li ions inserted into graphite. Detailed findings obtained from in situ dilatometry on the graphite electrode will be discussed in the presenation.
Confining Dendrite Growth Enabled By Ionically Conductive Interphase for Highly Stable Potassium Metal Anode
Authors: Park Jimin , Kim Jaekook , Hwang Jang-Yeon
Published: July 2022

Potassium metal has been considered as one of the ultimate anode for rechargeable potassium batteries because of its high theoretical capacity (686 mAh g-1) and low electrode potential (~2.93 V vs. SHE). However, K metal is thermodynamically instable in aprotic electrolyte and uneven K plating usually leads to dendritic K metal deposition, resulting in low Coulombic efficiency and safety concerns.1,2In this study, we introduce potential strategy to stabilize the K metal anode via simple chemical interface control. The robust and ionically conductive passivation layer can be controllably designed by the spontaneous chemical reaction when a K metal foil kept in contact with a liquid phase potassium-polysulfide (0.05M K2S5 dissolved in DEGDME);3 this provides a strong guiding effect to form an electronically and ionically conductive solid electrolyte interphase (SEI) layer, enabling a dense K plating with dendrite-free morphology. The unique characteristics of the functionalized K-metal is fully evidenced by the Operando optical microscopy and phase field modeling in electrodeposition process. Under practical constraints (i.e. using lean electrolyte and thin polymer separator), the functionalized K-metal anode exhibits the ultra-long-term K plating-stripping cycles over 1200 h in a symmetrical cells and further highlights a practical applicability with high areal capacity and fast charging-discharging capability in full-cells using TiS2 cathode.

References

U.-H. Kim, G.-T. Park, B.-K. Son, G. W. Nam, J. Liu, L.-Y. Kuo, P. Kaghazchi, C. S. Yoon and Y.-K. Sun, Nat. Energy, 2020, 5, 860.

J.-Y. Hwang, S.-T. Myung and Y.-K. Sun, Adv. Funct. Mater., 2018, 28, 1802938.

J.-Y. Hwang, H. M. Kim, C. S. Yoon and Y.-K. Sun, ACS Energy Lett., 2018, 3, 540-541.
In-Situ Characterization of Molecular Processes at the Anode/Na3SbS4 Electrolyte Interface in All-Solid-State Sodium Batteries
Authors: Xie Geng , Wen Fuwei , Wu Qichao , You Xiang , Xie Geng , Sang Lingzi
Published: July 2022

Sulfur based solid-state Na+ conductors exhibit high ionic conductivity and are promising candidates for electrolytes used in the next generation all-solid-state sodium-ion batteries. Sodium thioantimonate (Na3SbS4), for example, shows an ionic conductivity of 1 mS/cm, comparable to its liquid counterparts. In contrast to the well-known thiophosphate solid-state electrolytes, Na3SbS4 is chemically stable in dry air. However, solid-state Na-ion batteries assembled using Na3SbS4 as the electrolyte show a decaying performance over the charge and discharge cycles. This work characterized the molecular processes occurring at the interface between Na3SbS4 solid electrolyte and the anode. This interfacial chemistry was probed in real-time (in-situ) using Raman spectroscopy while the battery was in operation. Combined with the characterization results obtained from X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), we observed a largely irreversible decomposition of SbS4
3- while Na3SbS4 was directly exposed to negative potentials (vs. Na/Na+). Sb2S3 and elemental Sb are the two major decomposition byproducts formed and accumulated at the Na3SbS4/anode interface. This result unravels the decomposition mechanism at the Na3SbS4/anode interface in all-solid sodium batteries. It provides deep molecular insights into designing ideal protective layers at this critical interface.