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This work vividly demonstrates the rational design of VSe 2-x O x -SS cathode as an effective strategy to achieve fast and highly aqueous zinc ion storage. [Display omitted] • A simple and fast surface oxygen implantation strategy was designed to adjust the electronic structure of VSe 2 and form a surface protective film. • The VSe 2-x O x -SS-30 electrode showed higher specific capacity, better rate performance and more satisfactory cycling stability. • The zinc (de)intercalation and transformation reactions mechanism was revealed by some ex-situ/in-situ techniques. Interfacial chemical modification is an effective strategy to adjust the strong Coulombic ion-lattice interactions with high valence cations experienced by electrode materials, facilitating the reaction kinetic. In this paper, a simple and fast surface oxygen implantation strategy was designed to adjust the electronic structure of stainless steel (SS) supported vanadium diselenide (VSe 2) nanosheets and form a surface protective film, which effectively accelerates the reaction kinetics of Zn2+ and extends the cycle life of the battery. It is demonstrated that the conductivity, pseudocapacitance and specific capacity can be tuned by selectively introducing oxygen species to the surface, which provides an important reference for the design of electrodes with controlled surface chemistry. Density functional theory (DFT) calculations also confirm that the electronic structure can be adjusted by surface oxygen injection strategy, which not only improves the conductivity, but also adjusts the adsorption energy, thus providing favorable conditions for zinc ion storage. Benefiting from the selenium vacancies and pores generated by the removal of part of selenium, and the oxide film formed on the surfaces, the VSe 2-x O x -SS-30 electrode showed higher specific capacity (188.4 mAh/g at 0.5 A g−1 after 50 cycles), better rate performance (107.1 mAh/g at 4 A g−1) and more satisfactory cycling stability (83.1 mAh/g at 5 A g−1 after 1800 cycles) than VSe 2 -SS electrode. Importantly, the flexible quasi-solid-state VSe 2-x O x -SS-30//Zn battery also exhibits high specific capacity and excellent environmental adaptability. Furthermore, the zinc (de)intercalation and transformation reactions mechanism was revealed by some ex-situ/in-situ techniques. [ABSTRACT FROM AUTHOR]

[Display omitted] Photoelectrochemical (PEC) water splitting on semiconductor electrodes is considered to be one of the important ways to produce clean and sustainable hydrogen fuel, which is a great help in solving energy and environmental problems. Bismuth vanadate (BiVO 4) as a promising photoanode for photoelectrochemical water splitting still suffers from poor charge separation efficiency and photo-induced self-corrosion. Herein, we develop heterojunction-rich photoanodes composed of BiVO 4 and iron vanadate (FeVO 4), coated with nickel iron oxide (NiFeO x /FeVO 4 /BiVO 4). The formation of the interface between BiVO 4 and FeVO 4 (Bi-VO 4 -Fe bridges) enhances the interfacial interaction, resulting in improved performance. Meanwhile, high-conductivity FeVO 4 and NiFeO x oxygen evolution co-catalysts effectively enhance bulk electron/hole separation, interface water's kinetics and photostability. Concurrently, the optimized NiFeO x /FeVO 4 /BiVO 4 possesses a remarkable photocurrent density of 5.59 mA/cm2 at 1.23 V versus reversible hydrogen electrode (vs RHE) under AM 1.5G (Air Mass 1.5 Global) simulated sunlight, accompanied by superior stability without any decreased of its photocurrent density after 14 h. This work not only reveals the crucial role of built-in electric field in BiVO 4 -based photoanode during PEC water splitting, but also provides a new guide to the design of efficient photoanode for PEC. [ABSTRACT FROM AUTHOR]

Symmetric solid oxide fuel cells (SSOFCs) are attracting much attention due to their ability to improve chemical and thermal compatibility between electrolytes and electrodes and reduce manufacturing costs. The in-situ precipitating of electrode in reduction atmosphere has been proved to be an effective strategy to improve the maximum power density of SSOFCs. Herein, we use the Li(Ni x Co 2/3-x Mn 1/3)O 2 (LNCM) serial material as the symmetrical electrodes to fabricate SSOFCs, which are operated in normal and reverse mode. In reverse operation, the LNCM is firstly reduced by hydrogen and in-situ precipitates the Ni–Co alloy and Li 2 MnO 3. The electrochemical impedance spectra (EIS) indicates that the reduced product delivers excellent oxygen reducing activity as well as promising catalytic activity toward hydrogen oxidation reaction. Thus, the SSOFCs based on LNCM symmetric electrodes present superior electrochemical performance in the reverse operation. Moreover, in the LNCM serial samples, the atomic ratio of Ni and Co at the B site is adjusted to control the contents of in-situ precipitation for further optimizing the cell performance. Using Li[Ni 1/2 Co 1/6 Mn 1/3 ]O 2 as symmetric electrodes shows outstanding performance of 923 mW cm−2 at 550 °C. This work provides a reference scheme for electrode design of SSOFCs. [ABSTRACT FROM AUTHOR]

[Display omitted] The acidic CO 2 reduction reaction (CO 2 RR) offers a promising approach to mitigate CO 2 reactant loss and carbonate deposition, which are challenging issues in alkaline or neutral electrolytes. However, the hydrogen evolution reaction (HER) competes in the proton-rich environment near the catalyst surface as a side reaction, reducing the energy efficiency of generating multi-carbon (C 2+) products. In this work, we proposed a palladium (Pd) doping strategy in a copper (Cu)-based catalyst to stabilize polarized Cu0-Cu+ sites, thus enhancing the C C coupling step during the CO 2 RR while suppressing HER. At an optimal doping ratio of 6%, the Pd dopants were well dispersed as single atoms without aggregation, allowing for the stabilization of subsurface oxygen (O Sub), preserving the polarized Cu0-Cu+ active sites, and reducing the energy barrier of C C coupling. The Pd-doped Cu/Cu 2 O catalyst exhibited a peak Faradaic efficiency (FE) of 64.0% for C 2+ products with a corresponding C 2+ partial current density of 407.1 mA∙cm−2 at −2.18 V versus a reversible hydrogen electrode, a high CO 2 single-pass conversion efficiency (SPCE) of 73.2%, as well as a high electrochemical stability of ∼ 150 h at industrially relevant current densities, thus suggesting a potential approach for tuning the electrocatalytic CO 2 performances in acidic environments with higher carbon conversion efficiencies. [ABSTRACT FROM AUTHOR]

Silver-based catalytic materials have garnered considerable attention due to their high selectivity towards carbon monoxide (CO) in the electrochemical reduction (ECR) of CO2. However, the fabrication of silver-based ECR catalysts with high product selectivity and low competitive reaction activity using facile methods remains challenging. This study employed in situ electrochemical reconstruction to design high-performance silver-based catalytic materials for ECR, exploring performance enhancement mechanisms. Low-temperature electrochemical reconstruction was used to prepare silver-based catalysts, and the effects of metal ion chelating agents including ethylenediaminetetraacetic acid, citric acid, and sodium citrate were also investigated. Results showed that Ag-SC, namely the catalysts fabricated with sodium citrate as chelating agent, exhibited highly selective CO production, with faradaic efficiency of 93.23% at −0.85 V (versus reversible hydrogen electrode, RHE) and CO partial current density of −7.92 mA cm−2. Electrochemical impedance analysis confirmed low electron transfer resistance of Ag-SC, with 14.54 Ω, indicating superior electron transfer capability, and high ECR activity. Ag-SC also demonstrated excellent hydrophobicity, suppressing the competitive hydrogen evolution reaction and enhancing CO selectivity. In situ electrochemical reconstruction thus offers a simple, low-cost method for preparing silver-based catalysts tailored for ECR, with practical implications for electrode fabrication and catalytic material design. [ABSTRACT FROM AUTHOR]

Recently, tungsten oxide (WO 3) and bismuth vanadate (BiVO 4) have been considered as an intriguing combination for constructing a heterojunction for efficient photoelectrochemical (PEC) applications. Herein, we report the preparation of ternary WO 3 /BiVO 4 /NiCo layered double hydroxide (LDH) photoanodes for boosting photogenerated carrier transport and promotion of catalytic activity. WO 3 /BiVO 4 heterostructures were synthesized by a hydrothermal process of WO 3 nanoplates on a fluorine-doped tin oxide (FTO) glass substrate, followed by spin-coating for BiVO 4 materials. We investigated the effect of a NiCo LDH catalyst on PEC performance by controlling the growth temperatures of the NiCo LDH via hydrothermal synthesis. Moreover, the X-ray diffraction (XRD), Fourier‒transform infrared (FTIR) and X‒ray photoelectron spectroscopy (XPS) analyses revealed that the WO 3 /BiVO 4 heterojunction was retained after the NiCo LDH growth process regardless of synthesis temperatures. The PEC results verified that the WO 3 /BiVO 4 heterostructure with the optimized NiCo LDH catalyst (WBN60) possessed the best photocurrent density of 3.2 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE), which created improved charge separation and surface oxidation kinetics of photogenerated carriers. Consequentially, the smallest charge transfer resistance and recombination rate were achieved in the WBN60 electrode compared to others, indicating a much lower photoelectrode‒electrolyte interfacial resistance and the enhancement of photogenerated carrier transport by suppressing recombination. [ABSTRACT FROM AUTHOR]

The performance of electrocatalysts is critical for renewable energy technologies. While the electrocatalytic activity can be modulated through structural and compositional engineering following the Sabatier principle, the insufficiently explored catalyst-electrolyte interface is promising to promote microkinetic processes such as physisorption and desorption. By combining experimental designs and molecular dynamics simulations with explicit solvent in high accuracy, we demonstrated that dimethylformamide can work as an effective surface molecular pump to facilitate the entrapment of oxygen and outflux of water. Dimethylformamide disrupts the interfacial network of hydrogen bonds, leading to enhanced activity of the oxygen reduction reaction by a factor of 2 to 3. This strategy works generally for platinum-alloy catalysts, and we introduce an optimal model PtCuNi catalyst with an unprecedented specific activity of 21.8 ± 2.1 mA/cm2 at 0.9 V versus the reversible hydrogen electrode, nearly double the previous record, and an ultrahigh mass activity of 10.7 ± 1.1 A/mgPt. [ABSTRACT FROM AUTHOR]

Electrosynthesis of adipic acid (a precursor for nylon-66) from KA oil (a mixture of cyclohexanone and cyclohexanol) represents a sustainable strategy to replace conventional method that requires harsh conditions. However, its industrial possibility is greatly restricted by the low current density and competitive oxygen evolution reaction. Herein, we modify nickel layered double hydroxide with vanadium to promote current density and maintain high faradaic efficiency (>80%) within a wide potential window (1.5 ~ 1.9 V vs. reversible hydrogen electrode). Experimental and theoretical studies reveal two key roles of V modification, including accelerating catalyst reconstruction and strengthening cyclohexanone adsorption. As a proof-of-the-concept, we construct a membrane electrode assembly, producing adipic acid with high faradaic efficiency (82%) and productivity (1536 μmol cm−2 h−1) at industrially relevant current density (300 mA cm−2), while achieving >50 hours stability. This work demonstrates an efficient catalyst for adipic acid electrosynthesis with high productivity that shows industrial potential. Here, authors use a membrane electrode assembly is conducted to produce adipic acid with high faradaic efficiency and productivity at an industrially relevant current density, while achieving >50 hours stability. [ABSTRACT FROM AUTHOR]

TiO 2 is one of the most promising photoanodes in photoelectrochemical (PEC) water-splitting due to its chemical stability, corrosion resistance, and cost-effectiveness. However, the TiO 2 nanoparticles with high surface area and fast electron transfer have been grown on a Ti foil substrate through dielectric barrier discharge (DBD) plasma using Ar/O 2 mixture gas. Optical emission spectroscopy (OES) was utilized to detect the reactive species existing in DBD plasma discharge during the process of treating titanium foil. The field emission scanning electron microscopy (FE-SEM) images revealed the morphology of TiO 2 nanoparticles aggregated to form a microwire structure on a Ti foil substrate. The X-ray diffraction (XRD) patterns agreed with the anatase phase of the monoclinic TiO 2 nanoparticles. PEC measurement showed that the synthesis of TiO 2 nanoparticles using Ar/O 2 DBD plasma for a duration of 3-min resulted in the highest photocurrent response. This response reached the highest photocurrent density of 1.92 mA/cm2 at 1.23 V vs. RHE (versus a reversible hydrogen electrode). The photoconversion efficiency (ŋ) improved from 1.31 to 1.85 as the plasma treatment time increased from 1 min to 3 min. The remarkable performance can be attributed to the large surface area of the nanoparticles and their low charge resistance. Transient photocurrent-time curves are utilized to demonstrate the stability and repeatability of TiO 2 nanoparticles. Ar/O 2 DBD plasma treatment is a promising superior method to enhance the functionality of TiO 2 in PEC water-splitting applications, as demonstrated in the literature comparison. [ABSTRACT FROM AUTHOR]

Water electrolysis plays a central role in the transition to a fossil‐free society, but there are significant challenges to overcome in order to increase its availability on a large scale. Alkaline water electrolysis is a mature and scalable technology, although it has several disadvantages compared to electrolyzers working in acidic environments. In particular, the use of highly alkaline aqueous electrolytes can lead to corrosion, and the achieved current densities are relatively low. This study addresses the latter limitation by introducing a gas diffusion electrode (GDE) setup as a novel development tool that bridges the gap between research and practical applications in commercial devices such as fuel cells and electrolyzers. A high surface area Ni foam catalyst that can sustain exceptional oxygen evolution reaction (OER) current densities of up to 4 A cm−2 in a quasi‐steady‐state within our GDE setup operating in an alkaline environment is presented. The high performance of this Ni‐based benchmark catalyst is attributed to its deposition onto a mesh‐like porous transport layer (PTL) via hydrogen‐templated electrodeposition. This forms a porous foam‐like structure that augments the mass transport of the gaseous reactants at the GDE. [ABSTRACT FROM AUTHOR]

Integrated reference electrodes allow to deconvolute voltage contributions of anode and cathode and contribute to a better understanding of CO2 electrolyzers. However, in zero‐gap cell configurations, this integration can be challenging and obtaining error‐free data with such a setup is a non‐trivial task. This study compares five different methods to integrate a reference electrode into an alkaline zero‐gap CO2 electrolysis cell. Sources of error and measures to circumvent them are investigated and finite‐element simulation is used to gain a better understanding of observed effects. Placing a reference electrode into the inactive area of the cell is found to be a reliable method, as long as the placement of electrodes is sufficiently controlled. Sandwiching a wire quasi‐reference electrode between two membranes is especially useful for electrochemical impedance spectroscopy; however, it can affect the overall cell performance. Contacting the catalyst layer from the backside with a salt‐bridge is promising for localized measurements if sufficient reproducibility can be ensured. [ABSTRACT FROM AUTHOR]

The electrochemical conversion of glycerol into high-value chemicals through the selective glycerol oxidation reaction (GOR) holds importance in utilizing the surplus platform chemical component of glycerol. Nevertheless, it is still very limited in producing three-carbon chain (C3) chemicals, especially glyceric acid/glycerate, through the direct oxidation of its primary hydroxyl group. Herein, Pd microstructure electrodeposited on the Ni foam support (Pd/NF) is designed and fabricated to achieve a highly efficient GOR, exhibiting a superior current density of ca. 120 mA cm−2 at 0.8 V vs. reversible hydrogen electrode (RHE), and high selectivity of glycerate at ca. 70%. The Faradaic efficiency of C3 chemicals from GOR can still be maintained at ca. 80% after 20 continuous electrolysis runs, and the conversion rate of glycerol can reach 95% after 10-h electrolysis. It is also clarified that the dual-component interfaces constructed by the adjacent Pd and Ni sites are responsible for this highly efficient GOR. Specifically, Ni sites can effectively strengthen the generative capacity of the active adsorbed hydroxyl (OHad) species, which can steadily immigrate to the Pd sites, so that the surface adsorbed glycerol species are quickly oxidized into C3 chemicals, rather than breaking the C–C bond of glycerol; thus, neither form the C2/C1 species. This study may yield fresh perspectives on the electrocatalytic conversion of glycerol into high-value C3 chemicals, such as glyceric acid/glycerate. [ABSTRACT FROM AUTHOR]

[Display omitted] Electricity-driven nitrate (NO 3 −) to ammonia (NH 3) conversion presents a unique opportunity to simultaneously eliminate nitrate from sewage while capturing ammonia. However, the Faradaic efficiency and ammonia yield in this eight-electron process remain unsatisfactory, underscoring the critical need for more effective electrocatalysts. In this study, a RuCo alloy nanosheets electrodeposited on pinewood-derived three-dimensional porous carbon (RuCo@TDC) is introduced as a highly-efficient electrocatalyst for the nitrate reduction reaction. The RuCo@TDC catalyst exhibits superior electrocatalytic performance, achieving the highest NH 3 yield of 2.02 ± 0.11 mmol h−1 cm−2 at −0.6 V versus the reversible hydrogen electrode (vs. RHE) and the highest Faradaic efficiency of 95.7 ± 0.8 % at −0.2 V vs. RHE in an electrolyte mixture of 0.1 M KOH and 0.1 M KNO 3. Furthermore, the Zn-NO 3 − battery using RuCo@TDC as the cathode provides a maximum power density of 2.46 mW cm−2 and a satisfactory NH 3 yield of 1110 μg h−1 cm−2. [ABSTRACT FROM AUTHOR]

[Display omitted] Urea electrolysis is an appealing topic for hydrogen production due to its ability to extract hydrogen at a lower potential. However, it is plagued by sluggish kinetics and noble-metal catalyst requirements. Herein, we developed nickel-iron-layered double hydroxide (NiFe-LDH) nanolayers with abundant oxygen vacancies (O V) via synergistically etching nickel foam with Fe3+ and Cl- ions, enabling the efficient conversion of urea into H 2 and N 2. The synthesized O V -NiFe-LDH exhibits a lower potential (1.30 vs. reversible hydrogen electrode, RHE) for achieving 10 mA cm−2 in the urea oxidation reaction (UOR), surpassing most recently reported Ni-based electrodes. O V provides favorable conductivity and a large surface area, which results in a 4.1-fold in electron transport and a 5.1-fold increase in catalyst reactive sites. Density Functional Theory (DFT) calculations indicate that O V can lower the adsorption energy of urea, and enhance the bonding strength of *CONHNH, giving rise to improved UOR. This study provides a viable path toward economical and efficient production of high-purity hydrogen. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus (S. aureus) is recognized as one of the most common causes of gastroenteritis worldwide. This pathogen is a major foodborne pathogen that can cause many different types of various infections, from minor skin infections to lethal blood infectious diseases. Iron-regulated surface determinant protein A (IsdA) is an important protein on the S. aureus surface. It is responsible for iron scavenging via interaction with hemoglobin, haptoglobin, and hemoglobin-haptoglobin complexes. This study develops a portable aptasensor for IsdA and S. aureus detection using aptamer-modified gold nanoparticles (AuNPs) integrated into screen-printed carbon electrodes (SPCEs). The electrode system was made of three parts, including a carbon counter electrode, an AuNPs/carbon working electrode, and a silver reference electrode. The aptamer by Au–S bonding was conjugated on the electrode surface to create the aptasensor platform. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were utilized to investigate the binding interactions between the aptasensor and the IsdA protein. CV studies showed a linear correlation between varying S. aureus concentrations within the range of 101 to 106 CFU/mL, resulting in a limit of detection (LOD) of 0.2 CFU/mL. The results demonstrated strong reproducibility, selectivity, and sensitivity of the aptasensor for enhanced detection of IsdA, along with about 93% performance stability after 30 days. The capability of the aptasensor to directly detect S. aureus via the IsdA surface protein binding was further investigated in a food matrix. Overall, the aptasensor device showed the potential for rapid detection of S. aureus, serving as a robust approach to developing real-time aptasensors to identify an extensive range of targets of foodborne pathogens and beyond. [ABSTRACT FROM AUTHOR]

Cu2O has been successfully synthesized in different morphologies/sizes (nanoparticles and octahedrons) via a low-temperature chemical reduction method. Trapping metal ions in an ice cube and letting them slowly melt in a reducing agent solution is the simplest way to control the nanostructure. Enhancement of charge transfer and transportation of ions by Cu2O nanoparticles was shown by cyclic voltammetry and electrochemical impedance spectroscopy measurements. In addition, nanoparticles exhibited higher current densities, the lowest onset potential, and the Tafel slope than others. The Cu2O electrocatalyst (nanoparticles) demonstrated the Faraday efficiencies (FEs) of CO, CH4, and C2H6 up to 11.90, 76.61, and 1.87%, respectively, at −0.30 V versus reference hydrogen electrode, which was relatively higher FEs than other morphologies/sizes. It is mainly attributed to nano-sized, more active sites and oxygen vacancy. In addition, it demonstrated stability over 11 h without any decay of current density. The mechanism related to morphology tuning and electrochemical CO2 reduction reaction was explained. This work provides a possible way to fabricate the different morphologies/sizes of Cu2O at low-temperature chemical reduction methods for obtaining the CO, CH4, and C2H6 products from CO2 [ABSTRACT FROM AUTHOR]

Transition metals such as nickel and cobalt as an alternative to Pt and Pd can be used for oxygen evolution reactions (OERs) and hydrogen production reactions (HERs) in alkaline environments, facilitating green hydrogen production as a sustainable alternative to fossil fuels. In this study, an NiCo2O4 catalyst was produced by a sono-hydrothermal method using urea as a hydrolysis agent. The electrochemical performance of the catalyst-coated NiFelt electrode was evaluated at different KOH concentrations (0.25, 0.5, and 1 M) and four operating temperatures in the interval of 20–80 °C. The electrode characteristics were investigated via electrochemical spectroscopy (cyclic voltammetry, EIS, multistep chronopotentiometry, multistep chronoamperometry) using two different reference electrodes (Ag/AgCl and Hg/HgO), to obtain insight into the anodic and cathodic peaks. XRD, SEM, EDS, and TEM analyses confirmed the purity, structure, and nanoscale particle size (20–45 nm) of the NiCo2O4 catalyst. The electrode showed symmetric CV with Ag/AgCl, making this reference electrode more appropriate for capacitance measurements, while Hg/HgO proved advantageous for EIS in alkaline solutions due to reduced noise. The overpotential of the catalyst-coated NiFelt decreased by 108 mV at 10 mA/cm2 compared to bare NiFelt, showing a good potential for its application in anion exchange membranes and alkaline electrolyzers at an industrial scale. [ABSTRACT FROM AUTHOR]

Potassium-ion batteries (PIBs) are considered alternatives to lithium-ion batteries because of their comparatively cheaper manufacturing costs and lower potential (2.936 V compared to standard hydrogen electrodes). However, their large ionic radii and unstable structures hindered their satisfactory electrochemical performance. In this study, F–Sn/SnO x @C, a novel porous layered composite material, was prepared using NaCl as a template for in situ etching to obtain a promising negative electrode material for PIBs. The significant specific surface area of the composite material and the uniform embedding of tin nanoparticles within the layered porous carbon shell, contributed to its excellent potassium intercalation/deintercalation performance. Fluorine doping enhanced electron transfer, prevented nanoparticle aggregation, and improved electrolyte penetration and potassium ion migration. The PIBs prepared from this electrode showed high potassium storage capacity, outstanding cycle stability (retaining 263 mAh g−1 after 200 cycles at 100 mA g−1), and remarkable rate capability (505.6, 288.4, 193.5, 134.1, and 83.3 mAh g−1 at 0.1, 0.2, 0.3, 0.5, and 1.0 A g−1, respectively). These results provide a straightforward solution for improving the electrochemical performance of PIBs. [ABSTRACT FROM AUTHOR]

Clostridioides difficile is a widely distributed anaerobic pathogen. C. difficile infection is a serious problem in healthcare. Its biofilms have been found to exhibit biocorrosivity, albeit very little, but sufficient for it to correlate with biofilm growth/health. This work demonstrated the use of a disposable electrochemical biofilm test kit using two solid-state electrodes (a 304 stainless steel working electrode, and a graphite counter electrode, which also served as the reference electrode) in a 10 mL serum vial. It was found that the C. difficile 630∆erm Adp-4 mutant had a minimum inhibitory concentration (MIC) for vancomycin twice that of the 630∆erm wild type strain in biofilm prevention (2 ppm vs. 1 ppm by mass) on 304 stainless steel. Glutaraldehyde, a commonly used hospital disinfectant, was found ineffective at 2% (w/w) for the prevention of C. difficile 630∆erm wild type biofilm formation, while tetrakis(hydroxymethyl)phosphonium sulfate (THPS) disinfectant was very effective at 100 ppm for both biofilm prevention and biofilm killing. These antimicrobial efficacy data were consistent with sessile cell count and biofilm imaging results. Furthermore, the test kit provided additional transient biocide treatment information. It showed that vancomycin killed C. difficile 630∆erm wild type biofilms in 2 d, while THPS only required minutes. [ABSTRACT FROM AUTHOR]

Nickel–tungsten (Ni-W) alloys are gaining significant attention due to their superior hardness, wear resistance, anti-corrosion and electrochemical hydrogen evolution reaction (HER) activity. In this work, porous and crack Ni-W alloys with different W contents were prepared in a pyrophosphate bath. The key to forming a porous structure is a very high current density over 300 mA cm−2. The HER activity of porous and crack Ni-W alloys was studied by means of electrochemical technologies of linear sweep voltammetry (LSV), Tafel curves (Taf) and electrochemical impedance spectroscopy (EIS). Compared with the crack Ni-W alloy, the porous Ni-W alloy exhibits improved alkaline electrochemical HER performances, which can deliver a current density of 10 mA cm−2 at 166 mV (η10) vs. RHE (reversible hydrogen electrode). [ABSTRACT FROM AUTHOR]

Human liver subcellular fractions, including liver microsomes (HLM), liver cytosol fractions, and S9 fractions, are extensively utilized in in vitro assays to predict liver metabolism. The S9 fractions are supernatants of human liver homogenates that contain both microsomes and cytosol, which include most cytochrome P450 (CYP) enzymes and soluble phase II enzymes such as glucuronosyltransferases and sulfotransferases. This study reports on the direct electrochemistry and biocatalytic features of redox-active enzymes in S9 fractions for the first time. We investigated the electrochemical properties of S9 films by immobilizing them onto a high-purity graphite (HPG) electrode and performing cyclic voltammetry under anaerobic (Ar-saturated) and aerobic (O2-saturated) conditions. The heterogeneous electron transfer rate between the S9 film and the HPG electrode was found to be 14 ± 3 s−1, with a formal potential of −0.451 V vs. Ag/AgCl reference electrode, which confirmed the electrochemical activation of the FAD/FMN cofactor containing CYP450-reductase (CPR) as the electron receiver from the electrode. The S9 films have also demonstrated catalytic oxygen reduction under aerobic conditions, identical to HLM films attached to similar electrodes. Additionally, we investigated CYP activity in the S9 biofilm for phase I metabolism using diclofenac hydroxylation as a probe reaction and identified metabolic products using liquid chromatography–mass spectrometry (LC-MS). Investigating the feasibility of utilizing liver S9 fractions in such electrochemical assays offers significant advantages for pharmacological and toxicological evaluations of new drugs in development while providing valuable insights for the development of efficient biosensor and bioreactor platforms. [ABSTRACT FROM AUTHOR]

[Display omitted] Electrochemical nitrate reduction to ammonia is a promising alternative strategy for producing valuable ammonia. This prospective route, however, is subject to a slow electrocatalytic rate, which resulted from the weak adsorption and activation of intermediate species, and the low density electron cloud of active centers. To address this issue, we developed a novel approach by doping boron into metal hydroxyl oxides to adjust the electronic structure of active centers, and consequently, led a significant improvement in the Faraday efficiency upto approaching 100 %, as well as an impressive ammonia yield upto approximately 23 mg/h mgcat−1 at −0.6 V vs. reversible hydrogen electrode (RHE). Experimental data in mechanism demonstrate that the doped boron play a crucial role in modulating the local electronic environment surrounding the active sites Co. In situ Raman and FTIR spectra provide evidences that boron facilitates the formation of deoxidation and hydrogenation intermediates. Additionally, density functional theory (DFT) calculations support the notion that boron doping enhances the adsorption capability of intermediates, reduces the reaction barrier, and facilitates the desorption of NH 3. [ABSTRACT FROM AUTHOR]

The catalytic CO 2 conversion activity of well-defined M-N 3 C 1 sites is evaluated by density functional theory calculations and subsequent experimental tests. [Display omitted] Asymmetric nitrogen/carbon-coordinated single metal sites (M-N x C 4-x) outperform symmetric M-N 4 sites in carbon dioxide (CO 2) electroreduction. However, the challenge of crafting well-defined M-N x C 4-x sites complicates the understanding of their structure-catalytic performance relationship. In this study, we employ metallized N -confused tetraphenylporphyrin (M-NCTPP) to investigate CO 2 conversion on M-N 3 C 1 sites using both density functional theory and experimental methods. The optimal cobalt (Co)-N 3 C 1 site (Co-NCTPP) achieves a current density of 500 mA cm−2 and a carbon monoxide Faraday efficiency exceeding 90 % at −1.25 V vs. the reversible hydrogen electrode, surpassing the performance of Co-N 4 (Co-TPP). This research introduces a novel approach for designing and synthesizing high-activity heteroatom-anchored single metal sites, advancing fundamental understanding in the field. [ABSTRACT FROM AUTHOR]

[Display omitted] Regulating the electron structure and precise loading sites of metal-active sites within the highly conjugated and porous covalent-triazine frameworks (CTFs) is essential to promoting the nitrogen reduction reaction (NRR) performance for electrocatalytic ammonia (NH 3) synthesis under ambient conditions. Herein, experimental method and density functional theory (DFT) calculations were conducted to deeply probe the effect on NRR of the modulation of modulating the electron structure and the loading site of gold nanoparticles (Au NPs) in a two-dimensional (2D) CTF. 2D CTF synthesized using melem and hexaketocyclohexane octahydrate as building blocks (denoted as M−HCO−CTF) served as a robust scaffold for loading Au NPs to form an M−HCO−CTF@AuNP hybrid. DFT results uncovered that well-defined Au sites with tunable local structure were the active site for driving the NRR, which can significantly suppress the conversion of H+ into *H adsorption and enhance the nitrogen (N 2) adsorption/activation. The overlapped Au (3 d) and *N 2 (2 p) orbitals lowered the free energy of the rate-determining step to form *NNH, thereby accelerating the NRR. The M−HCO−CTF@AuNPs electrocatalyst exhibited a large NH 3 yield rate of 66.3 μg h−1 mg−1 cat. and a high Faraday efficiency of 31.4 % at − 0.2 V versus reversible hydrogen electrode in 0.1 M HCl, superior to most reported CTF-based ones. This work can provide deep insights into the modulation of the electron structure of metal atoms within a porous organic framework for artificial NH 3 synthesis through NRR. [ABSTRACT FROM AUTHOR]

[Display omitted] • Atomically dispersed catalyst with single Cu atom and atomic Ni clusters was prepared. • Cu SA Ni AC /NMHCS achieves a high FE CO of over 90% across a wide potential range. • Cu SA Ni AC /NMHCS shows the highest FE CO of 98 % at − 0.9 V vs. RHE. • Cu SA Ni AC /NMHCS exhibits excellent long-term stability for CO 2 RR to produce CO. • Positively shifted ε d of Ni 3 d orbital contributes to the enhanced CO 2 RR performance. The rational design of catalysts with atomic dispersion and a deep understanding of the catalytic mechanism is crucial for achieving high performance in CO 2 reduction reaction (CO 2 RR). Herein, we present an atomically dispersed electrocatalyst with single Cu atom and atomic Ni clusters supported on N-doped mesoporous hollow carbon sphere (Cu SA Ni AC /NMHCS) for highly efficient CO 2 RR. Cu SA Ni AC /NMHCS demonstrates a remarkable CO Faradaic efficiency (FE CO) exceeding 90% across a potential range of −0.6 to −1.2 V vs. reversible hydrogen electrode (RHE) and achieves its peak FE CO of 98% at −0.9 V vs. RHE. Theoretical studies reveal that the electron redistribution and modulated electronic structure—notably the positive shift in d-band center of Ni 3 d orbital—resulting from the combination of single Cu atom and atomic Ni clusters markedly enhance the CO 2 adsorption, facilitate the formation of *COOH intermediate, and thus promote the CO production activity. This study offers fresh perspectives on fabricating atomically dispersed catalysts with superior CO 2 RR performance. [ABSTRACT FROM AUTHOR]

Monomers: gentian violet (GV), brilliant green (BG), aniline, and methyl violet (MV), as well as their copolymers, were electropolymerized and used to modify glassy carbon electrode (GCE) by enhancing the sensitivity of the electrode. This is due to their special characteristics of sensing ability of the electropolymerized polymers. The electropolymerization and characterization of these monomers and their copolymers were done using cyclic voltammetry (CV) on GCE as a working electrode against Ag/AgCl reference electrode and platinum wire as the counter electrode. The copolymers showed higher current peaks than their corresponding homopolymers. The electrochemical characterization of these polymers and copolymers was studied by scan rate effect each between 10 and 300 mV/s and pH effect between 1.56 and 5.30. After being modified by the copolymers: poly(BG-GV) and poly(BG-MV), the modified GCE showed good results in resolving the peaks of ascorbic acid and uric acid which otherwise showed an overlapped broad peak on bare GCE. The CV in bare GCE was scanned at different scan rates of 4 mM K3[Fe(CN)6] in 1 M KNO3 solution. The square root of scan rate dependence of peak current was plotted and the Randles–Sevcik equation was applied to determine the diffusion coefficient of Fe(CN)63− ion and which was 1.13 × 10–14 cm2/s. This was used to determine the area of the modified electrode after running the CV of 4 mM K3[Fe(CN)6] in 1 M KNO3 at different scan rates. Therefore, the electrochemical polymerization of organic dye polymers was able to increase the sensitivity of the electrode by increasing its area. [ABSTRACT FROM AUTHOR]

This study investigates the impact of the uranium electrodeposition process on a boron-doped diamond electrode (BDD) surface at varying potentials as a means of environmental uranium remediation. The chronoamperometry technique was employed for the electrodeposition process, applying potentials ranging from − 0.60 to − 2.00 V vs. the reversible hydrogen electrode (RHE). A 2-mM uranyl acetate dihydrate (UO2(C2H3O2)2·2H2O) solution in 0.1-M KClO4 served as a model uranyl ion (UO22+) source. Analysis using scanning electron microscopy, energy-dispersive X-ray fluorescence spectroscopy, and atomic force microscopy (AFM) confirmed the presence of uranium and the formation of a thin layer on the electrode surface. Roughness measurements obtained through AFM analysis at different applied potentials vs. RHE were compared before and after uranium electrodeposition at BDD electrodes. Additionally, the identification of various uranium oxides resulting from the electrodeposition procedures was conducted using X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. These analyses revealed the presence of UO2, UO3, and U3O8 on the BDD electrode surface due to the electrochemical deposition process, with a notable proportion of U3O8 observed. Ultimately, the optimal potential for efficient U6+ remediation from aqueous media and the formation of a homogenous thin layer conducive to nuclear technology development was determined to be − 1.75 V vs. RHE. [ABSTRACT FROM AUTHOR]

We propose an in situ gas etching-thermal assembly strategy to simultaneously create mesopore-dominated carbon cores with ultrathin carbon-layer shells fully decorated with highly dispersed Mn-N 4 single-atom sites, which was used as a highly active and stable ORR catalyst in zinc-air batteries. [Display omitted] Applications of zinc-air batteries are partially limited by the slow kinetics of oxygen reduction reaction (ORR); Thus, developing effective strategies to address the compatibility issue between performance and stability is crucial, yet it remains a significant challenge. Here, we propose an in situ gas etching-thermal assembly strategy with an in situ -grown graphene-like shell that will favor Mn anchoring. Gas etching allows for the simultaneous creation of mesopore-dominated carbon cores and ultrathin carbon layer shells adorned entirely with highly dispersed Mn-N 4 single-atom sites. This approach effectively resolves the compatibility issue between activity and stability in a single step. The unique core–shell structure allows for the full exposure of active sites and effectively prevents the agglomerations and dissolution of Mn-N 4 sites in cores. The corresponding half-wave potential for ORR is up to 0.875 V (vs. reversible hydrogen electrode (RHE)) in 0.1 M KOH. The gained catalyst (Mn-N@Gra-L)-assembled zinc-air battery has a high peak power density (242 mW cm−2) and a durability of ∼ 115 h. Furthermore, replacing the zinc anode achieved a stable cyclic discharge platform of ∼ 20 h at varying current densities. Forming more fully exposed and stable existing Mn-N 4 sites is a governing factor for improving the electrocatalytic ORR activity, significantly cycling durability, and reversibility of zinc-air batteries. [ABSTRACT FROM AUTHOR]

Electrochemical CO2 reduction (ECR) to value-added products is regarded as a sustainable strategy to mitigate global warming and energy crisis, and designing highly efficient and robust catalysts is essential. In this work, transition metal sulfides (TMS)-decorated CuS microflower-like structures were prepared via the one-pot hydrothermal synthesis method for ECR to CO, and the influence of TMS doping on ECR performance was demonstrated. Characterization of the catalysts was performed using XRD, FESEM-EDS, N2 physisorption, and XPS, revealing the successful loading of TMS, the formation of microflower-like architectures and the generation of sulfur vacancies. Electrochemical tests demonstrated that doping ZnS, Bi2S3, CdS and MoS2 improved the intrinsic CO2 reduction activity of the CuS catalyst. Particularly, the MoS2-CuS composite catalyst with imperfect petal-like structure showed uniform distribution of edge Mo sites, which worked synergistically with the formed grain boundaries (GBs) and undercoordinated S vacancy sites in promoting CO2 activation, stabilizing *COOH adsorption, facilitating *CO desorption, and lowering the energy barrier of the potential-limiting step for improved CO selectivity. The MoS2-CuS catalyst achieved a maximum CO selectivity of 83.2% at –0.6 V versus the reversible hydrogen electrode (RHE) and a high CO cathodic energetic efficiency of 100%. At this potential, the catalyst maintained stable catalytic activity and CO selectivity during a 333-min electrolysis process. The findings will offer a promising avenue for the development of efficient and stable catalysts for CO production from ECR. [ABSTRACT FROM AUTHOR]

Wearable sensors, specifically microneedle sensors based on electrochemical methods, have expanded extensively with recent technological advances. Today's wearable electrochemical sensors present specific challenges: they show significant modulus disparities with skin tissue, implying possible discomfort in vivo, especially over extended wear periods or on sensitive skin areas. The sensors, primarily based on polyethylene terephthalate (PET) or polyimide (PI) substrates, might also cause pressure or unease during insertion due to the skin's irregular deformation. To address these constraints, we developed an innovative, wearable, all-fiber-structured electrochemical sensor. Our composite sensor incorporates polyurethane (PU) fibers prepared via electrospinning as electrode substrates to achieve excellent adaptability. Electrospun PU nanofiber films with gold layers shaped via thermal evaporation are used as base electrodes with exemplary conductivity and electrochemical catalytic attributes. To achieve glucose monitoring, gold nanofibers functionalized by gold nanoflakes (AuNFs) and glucose oxidase (GOx) serve as the working electrode, while Pt nanofibers and Ag/AgCl nanofibers serve as the counter and reference electrode. The acrylamide-sodium alginate double-network hydrogel synthesized on electrospun PU fibers serves as the adhesive and substance-transferring layer between the electrodes. The all-fiber electrochemical sensor is assembled layer-by-layer to form a robust structure. Given the stretchability of PU nanofibers coupled with a high specific surface area, the manufactured porous microneedle glucose sensor exhibits enhanced stretchability, superior sensitivity at 31.94 μA (lg(mM))−1 cm−2, a broad detection range (1–30 mM), and a significantly low detection limit (1 mM, S/N = 3), as well as satisfactory biocompatibility. Therefore, the novel electrochemical microneedle design is well-suited for wearable or even implantable continuous monitoring applications, thereby showing promising significant potential within the global arena of wearable medical technology. [ABSTRACT FROM AUTHOR]

In this paper, a CuSCN hole transport layer (HTL) is introduced between BiVO 4 and NiFeO x oxygen evolution cocatalyst (OEC) to form BiVO 4 /CuSCN/NiFeO x photoanode. Characterization and DFT calculations suggest that the high PEC performance is attributed to the incorporation of CuSCN as a HTL, which effectively facilitates charge transfer and accelerates the water oxidation kinetics, resulting in an enhanced PEC water splitting performance (5.65 mA cm−2 at 1.23 V vs. RHE). [Display omitted] • BiVO 4 /CuSCN/NiFeO x photoanode prepares by inserting CuSCN between BiVO 4 and NiFeO x. • The CuSCN promotes the transfer of holes from BiVO 4 to NiFeO x OEC. • The CuSCN exhibits enhanced OER activity and accelerates water oxidation kinetics. • BiVO 4 /CuSCN/NiFeO x photoanode achieves enhanced PEC water splitting performance. Modification of oxygen evolution co-catalyst (OEC) on the surface of bismuth vanadate (BiVO 4) can effectively improve the kinetics of water oxidation, but it is still limited by the small hole extraction driving force at the BiVO 4 /OEC interface. Modulating the BiVO 4 /OEC interface with a hole transfer layer (HTL) is expected to facilitate hole transport from BiVO 4 to the OEC surface. Herein, a copper(I) thiocyanate (CuSCN) HTL is inserted between BiVO 4 and NiFeO x OEC to create BiVO 4 /CuSCN/NiFeO x photoanode, resulting in a significant enhancement of photoelectrochemical (PEC) water splitting performance. From electrochemical analyses and density functional theory (DFT) simulations, the markedly enhanced PEC performance is attributed to the insertion of CuSCN as an HTL, which promotes the extraction of holes from BiVO 4 surface and boosts the water oxidation kinetics. The optimal photoanode achieves a photocurrent density of 5.6 mA cm−2 at 1.23 V versus the reversible hydrogen electrode (vs. RHE) and an impressive charge separation efficiency of 96.2 %. This work offers valuable insights into the development of advanced photoanodes for solar energy conversion and emphasizes the importance of selecting an appropriate HTL to mitigate recombination at the BiVO 4 /OEC interface. [ABSTRACT FROM AUTHOR]

High-purity ethylene production from CO2 electroreduction (CO2RR) is a coveted, yet arduous feat because the product stream comprises a blend of unreacted CO2, H2, and other off-target CO2 reduction products. Here we present an indirect reduction strategy for CO2-to-ethylene conversion, one that employs 2-bromoethanol (Br-EO) as a mediator. Br-EO is initially generated from CO2RR and subsequently undergoes reduction to ethylene without the need for energy-intensive separation steps. The optimized AC-Ag/C catalyst with Cl incorporation reduces the energy barrier of the debromination step during Br-EO reduction, and accelerates the mass-transfer process, delivering a 4-fold decrease of the relaxation time constant. Resultantly, AC-Ag/C achieved a FEethylene of over 95.0 ± 0.36% at a low potential of −0.08 V versus reversible hydrogen electrode (RHE) in an H-type cell with 0.5 M KCl electrolyte, alongside a near 100% selectivity within the range of −0.38 to −0.58 V versus RHE. Through this indirect strategy, the average ethylene purity within 6-hour electrolysis was 98.00 ± 1.45 wt%, at −0.48 V (vs RHE) from the neutralized electrolyte after CO2 reduction over the Cu/Cu2O catalyst in a flow-cell. Producing high-purity ethylene from direct CO2 electroreduction is challenging due to unwanted byproducts and unreacted CO2. Here, authors introduce an indirect method using 2-bromoethanol as a mediator, which reduces to ethylene with near-unity selectivity over an Ag catalyst. [ABSTRACT FROM AUTHOR]

Challenges in direct catalytic oxidation of biomass-derived aldehyde and alcohol into acid with high activity and selectivity hinder the widespread biomass application. Herein, we demonstrate that a Pd/Ni(OH)2 catalyst with abundant Ni2+-O-Pd interfaces allows electrooxidation of 5-hydroxymethylfurfural to 2, 5-furandicarboxylic acid with a selectivity near 100 % and 2, 5-furandicarboxylic acid yield of 97.3% at 0.6 volts (versus a reversible hydrogen electrode) in 1 M KOH electrolyte under ambient conditions. The rate-determining step of the intermediate oxidation of 5-hydroxymethyl-2-furancarboxylic acid is promoted by the increased OH species and low C–H activation energy barrier at Ni2+-O-Pd interfaces. Further, the Ni2+-O-Pd interfaces prevent the agglomeration of Pd nanoparticles during the reaction, greatly improving the stability of the catalyst. In this work, Pd/Ni(OH)2 catalyst can achieve 100% 5-hydroxymethylfurfural conversion and >90% 2, 5-furandicarboxylic acid selectivity in a flow-cell and work stably over 200 h under a fixed cell voltage of 0.85 V. Catalytic oxidation of biomass-derived aldehydes and alcohols into acids is challenging due to low activity and selectivity. Here the authors report a Pd/Ni(OH)2 electrocatalyst with abundant Ni2+-O-Pd interfaces that enables efficient electrooxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid with high selectivity and product yield. [ABSTRACT FROM AUTHOR]

Photoelectrochemical water splitting is a promising technique for converting solar energy into low‐cost and eco‐friendly H2 fuel. However, the production rate of H2 is limited by the insufficient number of photogenerated charge carriers in the conventional photoelectrodes under 1 sun (100 mW cm−2) light. Concentrated solar light irradiation can overcome the issue of low yield, but it leads to a new challenge of stability because the accelerated reaction alters the surface chemical composition of photoelectrodes. Here, it is demonstrated that loading Pt nanoparticles (NPs) on single crystalline GaN nanowires (NWs) grown on n+‐p Si photoelectrode operates efficiently and stably under concentrated solar light. Although a large number of Pt NPs detach during the initial reaction due to H2 gas bubbling, some Pt NPs which have an epitaxial relation with GaN NWs remain stably anchored. In addition, the stability of the photoelectrode further improves by redepositing Pt NPs on the reacted Pt/GaN surface, which results in maintaining onset potential >0.5 V versus reversible hydrogen electrode and photocurrent density >60 mA cm−2 for over 1500 h. The heterointerface between Pt cocatalysts and single crystalline GaN nanostructures shows great potential in designing an efficient and stable photoelectrode for high‐yield solar to H2 conversion. [ABSTRACT FROM AUTHOR]

This document is an editorial for a special issue on "Valuable Metals Recovery by Mineral Processing and Hydrometallurgy." It emphasizes the importance of metals for society and the need for efficient techniques to process ores and extract metals. The recovery of metals from secondary sources, such as mining waste, is also highlighted. The editorial discusses various aspects and challenges of metal recovery, including the use of flotation in mineral beneficiation and the application of hydrometallurgical methods. It presents studies on grinding media, pulp oxidation-reduction potential, and the use of new reagents for metal recovery. The editorial also explores the extraction of metals from refractory ores and mining waste. Overall, the papers in this special issue demonstrate the potential for recovering valuable metals from various sources using modern techniques and theoretical frameworks. [Extracted from the article]

Laser-inscribed graphene (LIG) is an emerging material for micro-electronic applications and is being used to develop supercapacitors, soft actuators, triboelectric generators, and sensors. The fabrication technique is simple, yet the batch-to-batch variation of LIG quality is not well documented in the literature. In this study, we conduct experiments to characterize batch-to-batch variation in the manufacturing of LIG electrodes for applications in electrochemical sensing. Numerous batches of 36 LIG electrodes were synthesized using a CO2 laser system on polyimide film. The LIG material was characterized using goniometry, stereomicroscopy, open circuit potentiometry, and cyclic voltammetry. Hydrophobicity and electrochemical screening (cyclic voltammetry) indicate that LIG electrode batch-to-batch variation is less than 5% when using a commercial reference and counter electrode. Metallization of LIG led to a significant increase in peak current and specific capacitance (area between anodic/cathodic curve). However, batch-to-batch variation increased to approximately 30%. Two different platinum electrodeposition techniques were studied, including galvanostatic and frequency-modulated electrodeposition. The study shows that formation of metallized LIG electrodes with high specific capacitance and peak current may come at the expense of high batch variability. This design tradeoff has not been discussed in the literature and is an important consideration if scaling sensor designs for mass use is desired. This study provides important insight into the variation of LIG material properties for scalable development of LIG sensors. Additional studies are needed to understand the underlying mechanism(s) of this variability so that strategies to improve the repeatability may be developed for improving quality control. The dataset from this study is available via an open access repository. [ABSTRACT FROM AUTHOR]

The goal of this research is to fabricate a novel type of highly active porous electrode material, based on stainless steel and dedicated to water electrolyzers. The main novelty of the presented work is the innovative application of the molten salts treatment, which allows the design of a highly developed porous structure, which characterizes significantly higher catalytic activity than untreated steel substrates. The equimolar mixture of NaCl and KCl with 3.5 mol% AlF3 was used as the molten salt. The surface modification procedure includes the deposition of an Al layer with application at the potential of −1.8 V and following dissolution at −0.9 V, to create a porous alloy surface. The cathodic polarization measurements of the prepared porous stainless steel electrodes were measured in a 10 mass% KOH solution. Moreover, the amount of hydrogen generated during constant voltage electrolysis with a hydrogen sensor in situ was also measured. The porous stainless steel alloy showed higher current density at lower potentials in the cathodic polarization compared to untreated stainless steel. The cathodic polarization measurements in alkaline solution showed that the porous 304 stainless steel alloy is an excellent cathode material. [ABSTRACT FROM AUTHOR]

The electroreduction of carbon dioxide (CO2) to multi‐carbon (C2+) compounds offers a viable approach for the up‐conversion of greenhouse gases into valuable fuels and feedstocks. Nevertheless, current industrial applications face limitations due to unsatisfactory conversion efficiency and high overpotential. Herein, a facile and scalable plasma fluorination method is reported. Concurrently, self‐evolution during CO2 electroreduction is employed to control the active sites of Cu catalysts. The copper catalyst modified with fluorine exhibits an impressive C2+ Faradaic efficiency (FE) of 81.8% at a low potential of −0.56 V (vs a reversible hydrogen electrode) in an alkaline flow cell. The presence of modified fluorine leads to the exposure and stabilization of high‐activity Cu+ species, enhancing the adsorption of *CO intermediates and the generation of *CHO, facilitating the subsequent dimerization. This results in a notably improved conversion efficiency of 13.1% and a significant reduction in the overpotential (≈100 mV) for the C2+ products. Furthermore, a superior C2+ FE of 81.6% at 250 mA cm−2, coupled with an energy efficiency of 31.0%, can be achieved in a two‐electrode membrane electrode assembly electrolyzer utilizing the fluorine‐modified copper catalyst. The strategy provides novel insights into the controllable electronic modification and surface reconstruction of electrocatalysts with practical potential. [ABSTRACT FROM AUTHOR]

The work presents novel composite catalytic materials—Ni and Co deposited on Magneli phase titania—and describes their complex characterization and integration into membrane electrode assemblies to produce hydrogen by electrochemical water splitting in cells with anion exchange membranes (AEMEC). Chemical composition, surface structure, and morphology were characterized by XRD and SEM analysis. The activity in the evolution of the partial electrode reactions of hydrogen (HER) and oxygen (OER) was assessed in an aqueous alkaline electrolyte (25 wt.% KOH) using linear sweep voltammetry. The interactive role of the support was investigated and discussed. Among the tested samples, the sample with 30 wt.% Co (Co30/MPT) demonstrated superior performance in the OER. The reaction started at 1.65 V, and at 1.8 V, the current density reached 75 mA cm−2. The HER is most efficient on the sample containing 40 wt.% Ni (Ni40/MPT), where the current density reaches 95 mA at a potential of −0.5 V. The change in catalytic efficiency compared to that of the unsupported Ni and Co is due to synergism resulting from electronic interactions between the transition metal having a hyper-d-electron character and hypo-d-electron support. The pre-selected catalysts were integrated in membrane electrode assembly (MEA) using commercial and laboratory-prepared anion-conductive membranes and tested in a custom-made AEMEC. The performance was compared to that of MEA with a commercial carbon-supported Pt catalyst. It was found that the MEA with newly prepared catalysts demonstrated better performance in long-term operation (50 mA cm−2 at 1.8 V in a 60 h durability test), which, combined with the higher cost efficiency, gave credence to considering this combination of materials as promising for AEMEC applications. [ABSTRACT FROM AUTHOR]

A small fraction of NO x (<1%) always exists in CO2 feedstock (e.g. exhausted gas), which can significantly reduce the efficiency of CO2 electroreduction by ∼30%. Hence, electrochemical denitrification is the precondition of CO2 electroreduction. The pH effect is a key factor, and can be used to tune the selectivity between N2 and N2O production in electrochemical denitrification. However, there has been much controversy for many years about the origin of pH dependence in electrocatalysis. To this end, we present a new scheme to accurately model the pH dependence of the electrochemical mechanism. An extremely small pH variation from pH 12.7 to pH 14 can be accurately reproduced for N2O production. More importantly, the obviously different pH dependence of N2 production, compared to N2O, can be attributed to a cascade path. In other words, the N2 was produced from the secondary conversion of the as-produced N2O molecule (the major product), instead of the original reactant NO. This is further supported by more than 35 experiments over varying catalysts (Fe, Ni, Pd, Cu, Co, Pt and Ag), partial pressures (20%, 50% and 100%) and potentials (from −0.2 to 0.2 V vs. reversible hydrogen electrode). All in all, the insights herein overturn long-lasting views in the field of NO electroreduction and suggest that rational design should steer away from catalyst engineering toward reactor optimization. [ABSTRACT FROM AUTHOR]

Improving the carrier separation efficiency plays a decisive role in designing and constructing a high‐efficiency photocatalysis reaction system. Derived from providing a directional transport channel for photogenerated carriers, three‐dimensional (3D) nanostructures greatly improve the charge separation efficiency. Herein, TiO2/ZnO (TZ)/g‐C3N4 3D hierarchical nanostructure was constructed to artificially simulate photosynthesis of green plants. The optimal TZ/g‐C3N4 photoanode exhibits a photocurrent density of 1.46 mA/cm2 at 1.23 V versus reversible hydrogen electrode potential, 1.6 times that of pure TiO2 (0.9 mA/cm2). Moreover, under constant illumination (100 mW/cm2), the hydrogen production reached 80 μmol/cm2 within 180 min. It is worth noting that the TZ/g‐C3N4 photoanode shows surprising stability, which is an important indicator for the practical application of the photoelectrode. The excellent photoelectrochemical performance benefits from the following two aspects: TZ nanotree structure provides a directional transport channel for photogenerated carriers, and the modification of TZ by g‐C3N4 extends the response range to the visible region. [ABSTRACT FROM AUTHOR]

Electrocatalytic water splitting is an essential hydrogen production method for resolving present energy shortage and progress toward more efficient technologies. For this purpose, a versatile and cheap electrocatalysts are the main challenge along the way. In this report, we synthesized vanadium telluride and carbon nanotube (VTe–CNT)‐based nanocomposite via facile hydrothermal route. The VTe–CNTs are characterized by X‐ray diffraction analysis, scanning electron microscopy, energy‐dispersive spectroscopy, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller. These characterizations depict nanosphere structures, morphology, and high surface area that maintains high porosity, which are essential for inclusive water‐splitting phenomena in 1.0 M solution of KOH. Additionally, the electrochemical performance of VTe–CNTs has shown best O2 evolution reactions activity with of onset potential of 1.42 V versus reversible hydrogen electrode and required 10 mA/cm2 of current density at 278 mV overpotential, which is excellent among other electrocatalysts, VTe (342 mV@10 mA/cm−2) and CNTs (365 mV@10mA/cm−2). Moreover, VTe–CNT exhibits remarkable stability for almost 20 h. It also requires a low onset potential of 0.05 V with a small Tafel slope of 47 mV/dec for H2 evolution reactions. Hence, this research might facilitate the easy transportation of electrons and open up the new era, serving as an excellent replacement for noble metal–derived materials. [ABSTRACT FROM AUTHOR]

Catechol (CT) is a phenolic compound widely used in various industrial sectors, but it is toxic; thus, there is a need for methods that aim to identify and quantify the existence of residues of this material in the environment. In this study a disposable printed electrochemical sensor was developed as an effective alternative for determining CT in water samples. The electrode, called SPEC, was manufactured using the screen-printing method using polyethylene terephthalate (PET) as a support, in which a conductive ink based on carbonaceous materials was used to print the working and auxiliary electrodes and a silver/silver chloride of ink on the reference electrode. The optimal ratio for the conductive ink was 6.25% carbon black, 35.42% graphite, and 58.33% nail polish. The ink obtained was characterized by scanning electron microscopy (SEM). The assessment of the effect of pH on the redox process showed Nernstian behavior (0.057 V pH−1), indicating that the process involves the same number of protons and electrons. Under optimized conditions, with 0.2 mol L−1 acetate buffer at pH 5.0, and by square wave voltammetry, the sensor presented sensitivity values of 0.31 μA L μmol−1, a detection limit of 5.96 μmol L−1, and a quantification limit of 19.87 μmol L−1. The sensor was applied to determine CT in tap water samples, and the results showed recoveries between 97.95 and 100.17%. [ABSTRACT FROM AUTHOR]

In this work, transition metal oxide (Bi2WO6) and metal organic framework (MIL-53(Al)) were used to prepare a composite. The MIL-53(Al) and Bi2WO6 powder were synthesized through hydrothermal route and the MIL-53(Al)/Bi2WO6 composite was prepared through impregnation technique. FESEM-EDX, XRD, FTIR and multi-point BET were used to characterize the MIL-53(Al), Bi2WO6 and composite. Electrochemical study was performed by employing a potentiostat and a 3-electrode cell, where platinum wire taken as counter electrode, active material-coated graphitic carbon felt as the working electrode and Ag/AgCl taken as reference electrode. MIL-53(Al) and Bi2WO6 were tested separately to determine the electrochemical efficiency, and it was found through galvanostatic charge–discharge method that they both have low energy densities when compared to the composite. The energy density of the composite was found to increase due to the characteristic changes resulting from the combination of MIL-53(Al) and Bi2WO6. Compared with the pristine MIL-53(Al) and Bi2WO6, the composite has exhibited higher specific capacitance of 554 F g−1 at 0.5 A g−1 and the lowest equivalent series resistance (ESR) resistance was obtained in electrochemical impedance spectroscopy study, which confirms that the MIL-53(Al)/Bi2WO6 hybrid has improved its performance as electrode material for supercapacitor application. [ABSTRACT FROM AUTHOR]

This work describes a novel methodology for measuring the potential distribution within the porous copper foam electrode of a zinc‐air/silver hybrid (ZASH) flow battery by using local potential probes. The suitability of dynamic hydrogen electrodes (DHEs) and a quasi‐reference electrode as probes is evaluated, with the latter chosen in view of stability. Liquid and solid‐phase potentials are recorded at varying applied current densities over multiple charge‐discharge cycles. Various zinc structures are found within specific overpotential ranges, with moss‐like structures appearing between 7.8 mV and 13.2 mV and the desired boulder structures in the range of 22 mV to 100 mV. Regardless of the current density, the highest liquid‐phase potentials are always measured in the outermost region of the porous foam near to the separator. In practice, this means that increasing the thickness of the copper foam over about 5 mm does not provide significant performance benefits. Conversely, solid‐phase potentials across the copper foam remain nearly uniform, resulting in negligible effects on local overpotential. The presented technique provides unique insights into the behavior of porous electrodes in electrochemical energy conversion technologies, facilitating the determination of the optimal properties for maximum efficiency, such as electrode thickness. [ABSTRACT FROM AUTHOR]

A Fe-Co dual-metal co-doped N containing the carbon composite (FeCo-HNC) was prepared by adjusting the ratio of iron to cobalt as well as the pyrolysis temperature with the assistance of functionalized silica template. Fe1Co-HNC, which was formed with 1D carbon nanotubes and 2D carbon nanosheets including a rich mesoporous structure, exhibited outstanding oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic activities. The ORR half-wave potential is 0.86 V (vs. reversible hydrogen electrode, RHE), and the OER overpotential is 0.76 V at 10 mA cm−2 with the Fe1Co-HNC catalyst. It also displayed superior performance in zinc–air batteries. This method provides a promising strategy for the fabrication of efficient transition metal-based carbon catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] The zinc-air battery (ZAB) performance and stability strongly depend on the structure of bifunctional electrocatalyst for oxygen reduction/evolution reaction (ORR/OER). In this work, we combine the tip and heterogeneous effects to construct cobalt/cobalt oxide heterostructure nanoarrays (Co/CoO-NAs). Due to the formed heterostructure, more oxygen vacancies are found for Co/CoO-NAs resulting in a 1.4-fold higher ORR intrinsic activity than commercial carbon supported platinum electrocatalyst (Pt/C) at 0.8 V versus reversible hydrogen electrode (vs. RHE). Moreover, a fast surface reconstruction is observed for Co/CoO-NAs during OER catalysis evidenced by in-situ electrochemical impedance spectroscopy and Raman tests. In addition, the tip effect efficiently lowers the mass transfer resistance triggering a low overpotential of 347 mV at 200 mA cm−2 for Co/CoO-NAs. The strong electronic interplay between cobalt (Co) and cobalt oxide (CoO) contributes to a stable battery performance during 1200 h galvanostatic charge–discharge test at 5 mA cm−2. This work offers a new avenue to construct high-performance and stable oxygen electrocatalyst for rechargeable ZAB. [ABSTRACT FROM AUTHOR]

A novel porous Ni matrix with optimal pore structure and adequate mechanical property is successfully prepared by a modified spark plasma sintering progress, while a self-supporting HER electrode of Ni 3 Se 2 @Porous Ni is subsequently obtained via a facile one-step hydrothermal synthesis. Such the Ni 3 Se 2 @Porous Ni electrode has performed a superior conductivity, excellent catalytic activity and robust durability, which can be attributed to the strong covalent bonding between Ni 3 Se 2 and Ni matrix, abundant active sites of the vertically arranged nanosheets, as well as the metallurgically bonded metal skeleton, exhibiting a fascinating potential for the industrial application. [Display omitted] Developing efficient and durable self-supporting catalytic electrodes is an important way for industrial applications of hydrogen evolution reaction. Currently, commercial nickel foam (NF)-based electrode has been widely used due to its good catalytic performance. However, the NF consisting of smooth skeleton surface and large pores not only exhibits poor conductivity but also provides insufficient space for catalyst decoration and sufficient adhesion, resulting in inadequate catalytic performance and poor durability of NF-based electrodes. In this paper, a novel three-dimensional porous Ni substrate with multangular skeleton surface and small pore structure was prepared by a modified spark plasma sintering technique, and subsequently Ni 3 Se 2 @Porous Ni electrode with a large number of Ni 3 Se 2 nanosheets uniformly distributed on the surface was obtained by one-step in-situ selenization. The electrode exhibits outstanding conductivity and catalytic hydrogen evolution reaction, providing a low overpotential of 183 mV at a current density of 100 mA cm−2. Due to the strong interfacial bonding between Ni and Ni 3 Se 2 , the Ni 3 Se 2 @Porous Ni electrode shows strong durability, which can work stably at 85 mA cm−2 for more than 200 h. This work provides an effective strategy for the rational preparation of metal substrates for efficient and durable self-supporting catalytic electrodes. [ABSTRACT FROM AUTHOR]

Introduction: A new analytical method based on the coupling of microextraction and microfluidics was developed and investigated for the pre-concentration, separation, and electrochemical detection of fenitrothion (FT) and parathion (PA) at the sub-ppm concentrations. Methods: In the first step, the microchip capillary electrophoresis technique was used to serve as a separation and detection system. Analytes were injected in the 40 mm long microchannel with 10 mm sidearms. Then, they were separated by applying a direct electrical field (+1800 V) between the buffer and detection reservoirs. 2-(n-morpholino)ethanesulfonic acid (MES) buffer (20 mM, pH 5) was used as a running buffer. The electrochemical detection was performed using three Pt microelectrodes with the width of working, counter, and reference electrodes (50, 250, and 250 µm, respectively) in the out-channel approach. Results: The system was devised to have the optimum detection potential equal to -1.2 V vs. pseudo-reference electrode. The dimensions of the SU-8 channel have 20 µm depth and 50 µm width. In the second step, an air-assisted liquid-liquid microextraction technique was used to extract and preconcentration of analytes from human blood plasma. Then, 1, 2 di-bromoethan was used as extractant solvent, the analytes were preconcentrated, and the sedimented solvent (50 µL) was evaporated in a 60 °C water bath followed by substitution of running buffer containing 10% ethanol. The optimal extraction cycles were found to be 8 with adding 1% NaCl to the aqueous phase. Analyzing time of the mentioned analytes was less than 100s, the precision range was 3.3 - 8.2 with a linear range of 0.8-100 ppm and 1.2-100 ppm for FT and PA, respectively. The extraction recoveries were about 91% and 87% for FT and PA, respectively. The detection limits for FT and PA were 240 and 360 ppb, respectively. Finally, the reliability of the method was investigated by GC-FID. Conclusion: The proposed method and device were validated and can be used as in situ and portable detection systems for detecting fenitrothion and parathion insecticides. [ABSTRACT FROM AUTHOR]

Highlights: What are the main findings? Square-wave power has the greatest influence on Ni cathode HER compared to step- and triangle-power. Increasing the amplitude of square-wave power enhances coated cathode's degradation. What is the implication of the main finding? Guidance for industrializing hydrogen production via renewable energy-coupled electrolytic water. Evaluation theory of cathode materials in electrolytic water. The combination of water electrolysis and renewable energy to produce hydrogen is a promising way to solve the climate and energy crisis. However, the fluctuating characteristics of renewable energy not only present a significant challenge to the use of water electrolysis electrodes, but also limit the development of the hydrogen production industry. In this study, the effects of three different types of waveforms (square, step, and triangle, which were used to simulate the power input of renewable energy) on the electrochemical catalysis behavior of Ni plate cathodes for HER was investigated. During the test, the HER performance of the Ni cathode increased at first and then slightly decreased. The fluctuating power led to the degradation of the Ni cathode surface, which enhanced the catalysis effect by increasing the catalytic area and the active sites. However, prolonged operation under power fluctuations could have damaged the morphology of the electrode surface and the substances comprising this surface, potentially resulting in a decline in catalytic efficiency. In addition, the electrochemical catalysis behavior of the prepared FeNiMo-LDH@NiMo/SS cathode when subjected to square-wave potential with different fluctuation amplitudes was also extensively studied. A larger amplitude of fluctuating power led to a change in the overpotential and stability of the LDH electrode, which accelerated the degradation of the cathode. This research provides a technological basis for the coupling of water electrolysis and fluctuating renewable energy and thus offers assistance to the development of the "green hydrogen" industry. [ABSTRACT FROM AUTHOR]