Search

[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 exponential growth of electrical resistivity tomography (ERT) methods for exploring the subsurface at large depths widened the applicability of the self-potential (SP) method, a passive geoelectrical technique suitable for a variety of purposes like mapping ore bodies or inferring fluid flow in the subsurface. Several new-generation resistivity meters have been designed to continuously log the electric potentials thus allowing for the identification of weak amplitude signals and resulting in deeper inversion models. In such approaches, long SP time-series are collected but are totally ignored as only marginal intervals are retained and analysed in the ERT procedure. The discarded SP records could be valuable although not collected using the traditional methodology, based on a reference electrode. We present an SP forward modelling feasibility study of different array techniques, based on numerical finite-element methods. The SP has been modelled in a variety of electrical settings to assess the imaging potentials of non-conventional (i.e. sparse gradient and full sparse gradient) arrays in comparison to traditional (i.e. fixed-base and the leapfrog) arrays. The analytic signal amplitude (ASA) algorithm was employed to compare numerical modelling results obtained from the different type of arrays, highlighting the great potentials of non-conventional arrays for the recognition of several sources of SP anomalies. The ASA maps, presenting a single peak centred over the targets, can significantly help in identifying the source anomalies for all the analysed array techniques. The cost-effectiveness along with the imaging capability of these non-conventional arrays constitute important benefits that could be exploited resulting in a systematic inclusion of SP analysis when collecting deep ERT data using distributed systems. [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]

Due to fossil fuel depletion and increasing pollution, researchers are now finding ways to develop alternative fuels. Recently, hydrogen became the most focused alternative that can act as a future fuel. Electrochemical water splitting is the cleanest method of producing oxygen and hydrogen from water. Costly noble metal-based materials are used for water splitting and oxygen generation, so there is a strong need to replace platinum with non-precious materials for water splitting. The morphology of the material has a considerable impact on its physical properties and performance. In this research work, we have synthesized flower-shaped nickel cobalt sulfide (NCS-AA) material via a facile hydrothermal method. The material was characterized using SEM and EDS for morphology observation and elemental analysis. The SEM results showed the formation of a flower-type morphology with a diameter of 500 nm to 2 µm and EDS analysis confirmed the presence of Ni, Co, and S. Further, electrochemical analysis was carried out to analyze its performance in oxygen evolution reaction (OER) by performing CV, LSV, and CA analysis techniques. NCS-AA demonstrated good OER activity with an overpotential of ~ 320 mV and a Tafel slope of 115 mV/dec versus a reversible hydrogen electrode for 10 mA/cm2 current density. Further, the stability of NCS-AA materials at 50 mA/cm2 and 200 mA/cm2 was excellent as examined using the chronopotentiometry technique. [ABSTRACT FROM AUTHOR]

While developing battery cells, the achievement of fast-charging capability is heavily dependent on avoiding metallic plating on the anode surface (i.e., lithium plating in lithium-ion cells). However, this objective hinges on the effectiveness of plating detection. Currently, measurement techniques are either inadequate in providing spatial, temporal, or causal information, incur high costs when employing, e.g., neutron imaging, or are lengthy due to destructive post-mortem examinations that additionally lack operando data. In this work, we demonstrate an ultrasound imaging method for operando visualization of the interior of a multi-layer pouch battery cell. Here we show that this method can non-invasively visualize the formation and stripping of lithium plating during cycling. Extensive reference electrode studies and ex-situ analysis verify the effectiveness of our method for plating detection. Ultimately, this work enables researchers and industry to significantly accelerate the development of new cell technologies and their optimized utilization. The authors have demonstrated a method for real-time imaging of the interior of a battery using ultrasound imaging. This approach reveals effects that hinder fast charging, enabling researchers to develop new batteries and optimize their utilization. [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]

The self-doping of oxygen vacancy and Ti3+ by electrochemical reduction (ER) method has been proved to be an effective means to improve the PEC performance of TiO2. However, the effect of the surface structure on ER treatment remains ambiguous. In this work, three kinds of nanostructured rutile TiO2 (nanowire arrays (TNWs), etched nanowire arrays (E-TNWs) and nanorod arrays (TNRs)) were reduced electrochemically to explore the factors influencing the ER process of rutile TiO2. The experimental results show that alkaline environment (1 M NaOH) is more conducive to the occurrence of ER reaction. And the reduced three kinds of nanostructured TiO2 photoanodes show a significantly higher photocurrent density of about 1.46, 1.65 and 1.45 mA cm−2 at 1.23 V vs. relative hydrogen electrode (RHE), respectively, which are 15, 16 and 1.1 times that of pristine TiO2. The different degrees of photocurrent density enhancement can be ascribed to the different degrees of electrochemical reduction of TiO2 with different crystallinity and exposed crystal facets as well as specific surface area. This study provides new insights into the mechanism of electrochemical reduction method. [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]

The self-doping of oxygen vacancy and Ti3+ by electrochemical reduction (ER) method has been proved to be an effective means to improve the PEC performance of TiO2. However, the effect of the surface structure on ER treatment remains ambiguous. In this work, three kinds of nanostructured rutile TiO2 (nanowire arrays (TNWs), etched nanowire arrays (E-TNWs) and nanorod arrays (TNRs)) were reduced electrochemically to explore the factors influencing the ER process of rutile TiO2. The experimental results show that alkaline environment (1 M NaOH) is more conducive to the occurrence of ER reaction. And the reduced three kinds of nanostructured TiO2 photoanodes show a significantly higher photocurrent density of about 1.46, 1.65 and 1.45 mA cm−2 at 1.23 V vs. relative hydrogen electrode (RHE), respectively, which are 15, 16 and 1.1 times that of pristine TiO2. The different degrees of photocurrent density enhancement can be ascribed to the different degrees of electrochemical reduction of TiO2 with different crystallinity and exposed crystal facets as well as specific surface area. This study provides new insights into the mechanism of electrochemical reduction method. [ABSTRACT FROM AUTHOR]

Green hydrogen production from water is one attractive route to non-fossil fuel and a potential source of clean energy. Hydrogen is not only a zero-carbon energy source but can also be utilized as an efficient storage of electrical energy generated through various other sources, such as wind and solar. Cost-effective and environmentally benign direct hydrogen production through neutral water (∼pH 7) reduction is particularly challenging due to the low concentration of protons. There is currently a major need for easy-to-prepare, robust, as well as active electrode materials. Herein we report three new molecular electrodes that were prepared by anchoring commercially available, and environmentally benign cobalt-containing electrocatalysts with three different ligand frameworks (porphyrin, phthalocyanine, and corrin) on a structurally modified graphite foil surface. Under the studied reaction conditions (over 7 h at 22°C), the electrode with Co-porphyrin is the most efficient for the water reduction with starting ∼740 mV onset potential (OP) (vs. RHE, current density 2.5 mA/cm2) and a Tafel slope (TS) of 103 mV/dec. It is followed by the molecular electrodes having Co-phthalocyanine [825 mV (OP), 138 mV/dec (TS)] and Vitamin-B12 (Co-corrin moiety) [830 mV (OP), 194 mv/dec (TS)]. A clear time-dependent improvement (>200 mV over 3 h) in the H2 production overpotential with the Co-porphyrin-containing cathode was observed. This is attributed to the activation due to water coordination to the Co-center. A long-term chronopotentiometric stability test shows a steady production of hydrogen from all three cathode surfaces throughout seven hours, confirmed using an H2 needle sensor. At a current density of 10 mA/cm2, the Co-porphyrin-containing electrode showed a TOF value of 0.45 s−1 at 870 mV vs. RHE, whereas the Co-phthalocyanine and Vitamin-B12-containing electrodes showed 0.37 and 0.4 s−1 at 1.22 V and 1.15 V (vs. RHE), respectively. [ABSTRACT FROM AUTHOR]

Regulating the adsorption of an intermediate on an electrocatalyst by manipulating the electron spin state of the transition metal is of great significance for promoting the activation of inert nitrogen molecules (N2) during the electrocatalytic nitrogen reduction reaction (eNRR). However, achieving this remains challenging. Herein, a novel 2D/2D Mott–Schottky heterojunction, Co9S8/Nb2CTx‐P, is developed as an eNRR catalyst. This is achieved through the in situ growth of cobalt sulfide (Co9S8) nanosheets over a Nb2CTx MXene using a solution plasma modification method. Transformation of the Co spin state from low (t2g6eg1) to high (t2g5eg2) is achieved by adjusting the interface electronic structure and sulfur vacancy of Co9S8/Nb2CTx‐P. The adsorption ability of N2 is optimized through high spin Co(II) with more unpaired electrons, significantly accelerating the *N2→*NNH kinetic process. The Co9S8/Nb2CTx‐P exhibits a high NH3 yield of 62.62 µg h−1 mgcat.−1 and a Faradaic efficiency (FE) of 30.33% at −0.40 V versus the reversible hydrogen electrode (RHE) in 0.1 m HCl. Additionally, it achieves an NH3 yield of 41.47 µg h−1 mgcat.−1 and FE of 23.19% at −0.60 V versus RHE in 0.1 m Na2SO4. This work demonstrates a promising strategy for constructing heterojunction electrocatalysts for efficient eNRR. [ABSTRACT FROM AUTHOR]

Substituting thermodynamically favorable ethanol oxidation reaction (EOR) for oxygen evolution reaction (OER) engenders high‐efficiency hydrogen production and generates high value‐added products as well. However, the main obstacles have been the low activity and the absence of an explicit catalytic mechanism. Herein, a heterostructure composed of amorphous vanadium oxide and crystalline nickel nitride (VOx−Ni3N) is developed. The heterostructure immensely boosts the EOR process, achieving the current density of 50 mA cm−2 at the low potential of 1.38 V versus reversible hydrogen electrode (RHE), far surpassing the sluggish OER (1.65 V vs RHE). Electrochemical impedance spectroscopy indicates that the as‐fabricated heterostructure can promote the adsorption of OH− and the generation of the reactive species (O*). Theoretical calculations further outline the dual polarization of the Ni site at the interface, specifically the asymmetric charge redistribution (interfacial polarization) and in‐plane polarization. Consequently, the dual polarization modulates the d‐band center, which in turn regulates the adsorption/desorption strength of key reaction intermediates, thereby facilitating the entire EOR process. Moreover, a VOx−Ni3N‐based electrolyzer, coupling hydrogen evolution reaction (HER) and EOR, attains 50 mA cm−2 at a low cell voltage of ≈1.5 V. This work thus paves the way for creating dual polarization through interface engineering toward broad catalysis. [ABSTRACT FROM AUTHOR]

This work shows how hydrophobicity and porosity can be incorporated into copper catalyst layers (CLs) for the efficient electroreduction of CO (CORR) in a flow cell. Oxide‐derived (OD) Cu catalysts are synthesized using K+ and Cs+ as templates, termed respectively as OD‐Cu‐K and OD‐Cu‐Cs. CLs, assembled from OD‐Cu‐K and OD‐Cu‐Cs, exhibit enhanced CORR performance compared to "unmodified" OD‐Cu CL. OD‐Cu‐Cs can notably reduce CO to C2+ products with Faradaic efficiencies (FE) as high as 96% (or 4% FE H2). During CO electrolysis at −3000 mA cm−2 (−0.73 V vs reversible hydrogen electrode), C2+ products and the alcohols are formed with respective current densities of −2804 and −1205 mA cm−2. The mesopores in the OD‐Cu‐Cs CL act as barriers against electrolyte flooding. Contact angle measurements confirm the CL's hydrophobicity ranking: OD‐Cu‐Cs > OD‐Cu‐K > OD‐Cu. The enhanced hydrophobicity of a catalyst is proposed to allow more triple‐phase (CO‐electrolyte‐catalyst) interfaces to be available for CORR. This study shows how the pore size‐hydrophobicity relationship can be harvested to guide the design of a less‐is‐more Cu electrode, which can attain high CORR current density and selectivity, without the additional use of hydrophobic polytetrafluoroethylene particles or dopants, such as Ag. [ABSTRACT FROM AUTHOR]

To design a high‐efficiency crystalline silicon (c‐Si) photocathode, the photovoltage and photocurrent generated by the device must be maximized because these factors directly affect the hydrogen evolution reaction (HER). In this study, a c‐Si p–n junction is used to enhance the photovoltage of the c‐Si photocathode, and a tapered microwire array structure is introduced to increase the photocurrent. When tapered microwire arrays are employed on the front surface of the c‐Si photocathode, a current density of ≈41.7 mA cm−2 is achieved at 0 VRHE (reversible hydrogen electrode); this current density is the highest among all reported photocathodes including c‐Si, approaching the theoretical maximum value for c‐Si. Furthermore, a Ni foil/Pt catalyst is introduced on the opposite side of the incident light, simultaneously serving as an electrocatalyst to reduce side reactions in the HER and encapsulation layer to prevent c‐Si from contacting the electrolyte. Thus, a stable device is developed using c‐Si photoelectrochemical cells that have an efficiency exceeding 97% for >1000 h. [ABSTRACT FROM AUTHOR]

Electrochemical conversion of nitrate (NO3−) to ammonia (NH3) is a potential way to produce green NH3 and remediate the nitrogen cycle. In this paper, an efficient catalyst of spherical CuO made by stacking small particles with oxygen‐rich vacancies is reported. The NH3 yield and Faraday efficiency are 15.53 mg h−1 mgcat−1 and 90.69%, respectively, in a neutral electrolyte at a voltage of ‐0.80 V (vs. reversible hydrogen electrode). The high activity of the electrodes results from changes in the phase and structure during electrochemical reduction. Structurally, there is a shift from a spherical structure with dense accumulation of small particles to a layered network structure with uniform distribution of small particles stacked on top of each other, thus exposing more active sites. Furthermore, in terms of phase, the electrode transitions from CuO to Cu/Cu(OH)2. Density functional theory calculations showed that Cu(OH)2 formation enhances NO3‐ adsorption. Meanwhile, the Cu(OH)2 can inhibit the competing hydrogen evolution reaction, while the formation of Cu (111) crystal surfaces facilitates the hydrogenation reaction. The synergistic effect between the two promotes the NO3‐ to NH3. Therefore, this study provides a new idea and direction for Cu‐based oxides in electrocatalytic NH3 production. [ABSTRACT FROM AUTHOR]

Transition metal‐nitrogen‐carbon (M‐N‐C) catalysts have emerged as promising candidates for electrocatalytic CO2 reduction reaction (CO2RR) due to their uniform active sites and high atomic utilization rate. However, poor efficiency at low overpotentials and unclear reaction mechanisms limit the application of M‐N‐C catalysts. In this study, Fe‐N‐C catalysts are developed by incorporating S atoms onto ordered hierarchical porous carbon substrates with a molecular iron thiophenoporphyrin. The well‐prepared FeSNC catalyst exhibits superior CO2RR activity and stability, attributes to an optimized electronic environment, and enhances the adsorption of reaction intermediates. It displays the highest CO selectivity of 94.0% at −0.58 V (versus the reversible hydrogen electrode (RHE)) and achieves the highest partial current density of 13.64 mA cm−2 at −0.88 V. Furthermore, when employed as the cathode in a Zn‐CO2 battery, FeSNC achieves a high‐power density of 1.19 mW cm−2 and stable charge–discharge cycles. Density functional theory calculations demonstrate that the incorporation of S atoms into the hierarchical porous carbon substrate led to the iron center becoming more electron‐rich, consequently improving the adsorption of the crucial reaction intermediate *COOH. This study underscores the significance of hierarchical porous structures and heteroatom doping for advancing electrocatalytic CO2RR and energy storage technologies. [ABSTRACT FROM AUTHOR]

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]

Pt-based intermetallic compound (IMC) nanoparticles have been considered the most promising catalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFC). Herein, we propose a strategy for producing ordered Pt3(CoNi) ternary IMC nanoparticles supported on N-doped carbon materials. Particularly, the Co and Ni are originally embedded into ZIF-derived carbon, which diffuse into Pt nanocrystals to form Pt3(CoNi) nanoparticles. Moreover, a thin layer of carbon develops outside of Pt3(CoNi) nanoparticles during the cooling process, which contributes to stabilizing the Pt3(CoNi) on carbon supports. The optimal Pt3(CoNi) nanoparticle catalyst has achieved significantly enhanced activity and stability, exhibiting a half-wave potential of 0.885 V vs reversible hydrogen electrode (RHE) and losing only 16 mV after 10,000 potential cycles between 0.6 and 1.0 V. Unlike the direct-use commercial carbon (VXC-72) for depositing Pt, we utilized ZIF-derived carbon containing dispersed Co and Ni nanocluster or nanoparticles to prepare ordered Pt3(CoNi) intermetallic catalysts. [ABSTRACT FROM AUTHOR]

Thin-film devices that transduce the chemical activity of ions into electronic signals are essential components in various applications, including healthcare diagnostics and environmental monitoring. Combinations of organic semiconductors (OSCs) and ionselective materials have been explored for developing solution-processable ion sensors. However, the necessity of reference electrodes (REs) and operational stability in ionpermeable OSCs have posed questions regarding whether reliable measurements with thin-film components are attainable with OSCs. Herein, we report electric double-layer transistors (EDLTs) with OSCs in single-crystal forms for ion sensing. Our EDLTs demonstrated high operational stability, with a one-to-one relationship between the source electrode potential and device resistance, and served as quasi-REs (qRE). When our EDLT is served as qRE, its drift was as small as 0.5 mV/h and comparable to that of commonly employed REs. In our system, the semiconductor-electrolyte interface is self-passivated by the alkyl chains of OSCs in single-crystal structures, with the two-dimensional transport layer appearing unaltered upon gating. EDLT arrays with ion-selective and nonselective liquid junctions enable ion concentration sensing without a conventional RE. These findings provide opportunities to develop thin-film devices based on OSCs for easy integration and reliable measurements. [ABSTRACT FROM AUTHOR]

Polymeric carbon nitride (CN) has emerged as a promising photoanodic material in water‐splitting photoelectrochemical cells (PEC). However, the current deposition methods of CN layers on substrates usually include a long heating process at 500−550 °C, which might cause sublimation or decomposition of the CN monomers and destruction of the substrate, leading to a nonuniform CN film. Herein, a simple, fast, and scalable energy‐economic procedure to synthesize homogenous CN films is introduced. The predesigned CN monomers film is subjected for several minutes to higher temperatures than the standard calcination procedure. The short heating process allows the formation of a uniform CN layer, with excellent contact with the substrate and good activity as a photoanode in PEC. The optimal CN photoanode reaches photocurrent densities of ≈200 μA cm−2 at 1.23 versus reversible hydrogen electrode in neutral and acidic solutions and 120 μA cm−2 in a basic solution. [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]

This article describes the process of fabricating an integrated all-solid electrode (IASE) by integrating thin films of titanium dioxide (TiO2) and silver/silver chloride (Ag/AgCl) onto an indium tin oxide (ITO) substrate. The fabrication of a pH sensing electrode (SE) involved utilizing a spin-coated thin film composed of TiO2. Thermally produced thin films of Ag/AgCl were used to develop solid reference electrodes (RE). The present work examined the impact of the drying process on the pH sensitivity and linearity of the lowtemperature deposited IASE. The drying procedure was carried out within a temperature range from room temperature to 100°C. The investigation involved the examination of crystallinity, surface morphology, and thin film composition through the utilization of field effect scanning electron microscopy (FESEM), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) methods. In addition, a comparison was made between the pH sensing performance of the IASE and a commercially available Ag/AgCl RE. The findings of this research demonstrate that the IASE sample, which underwent a drying process at a temperature of 100°C, exhibited remarkable sensitivity and linearity values of 66.7 mV/pH and 0.9827, separately, when compared to the commercially available RE. [ABSTRACT FROM AUTHOR]

The electroreduction of nitrate offers a promising, sustainable, and decentralized route to generate valuable ammonia. However, a key challenge in the nitrate reduction reaction is the energy efficiency of the reaction, which requires both a high ammonia yield rate and a high Faradaic efficiency of ammonia at a low working potential (≥−0.2 V versus reversible hydrogen electrode). We propose a bimetallic Co–B/Ru12 electrocatalyst which utilizes complementary effects of Co–B and Ru to modulate the quantity of adsorbed hydrogen and to favor the specific hydrogenation for initiating nitrate reduction reaction at a low overpotential. This effect enables the catalyst to achieve a Faradaic efficiency for ammonia of 90.4 ± 9.2% and a remarkable half-cell energy efficiency of 40.9 ± 4% at 0 V versus reversible hydrogen electrode. The in-situ electrochemical reconstruction of the catalyst contributes to boosting the ammonia yield rate to a high level of 15.0 ± 0.7 mg h−1 cm−2 at −0.2 V versus reversible hydrogen electrode. More importantly, by employing single-entity electrochemistry coupled with identical location transmission electron microscopy, we gain systematic insights into the correlation between the increase in the catalyst's active sites and its structural transformations during the nitrate reduction reaction. Nitrate electroreduction is a promising method for sustainable NH3 production, but the challenge lies in achieving high yield and efficiency at low potentials. Here the authors report a bimetallic Co–B/Ru12 catalyst for improved activity and unveil the dynamic change of the active sites using operando techniques and single entity experiments. [ABSTRACT FROM AUTHOR]

The utilization of single atoms (SAs) as trifunctional electrocatalyst for nitrogen reduction, oxygen reduction, and oxygen evolution reactions (NRR, ORR, and OER) is still a formidable challenge. Herein, we devise one‐pot synthesized palladium SAs stabilized on nitrogen‐doped carbon palladium SA electrocatalyst (Pd‐SA/NC) as efficient trifunctional electrocatalyst for NRR, ORR, and OER. Pd‐SA/NC performs a robust catalytic activity toward NRR with faradaic efficiency of 22.5% at −0.25 V versus reversible hydrogen electrode (RHE), and the relative Pd utilization efficiency is enhanced by 17‐fold than Pd‐NP/NC. In addition, the half‐wave potential reaches 0.876 V versus RHE, amounting to a 58‐time higher mass activity than commercial Pt/C. Moreover, the overpotential at 10 mA cm−2 is as low as 287 mV for Pd‐SA/NC, outperforming the commercial IrO2 by 360 times in turnover frequency at 1.6 V versus RHE. Accordingly, the assembled rechargeable zinc‐air battery (ZAB) achieves a maximum power density of 170 mW cm−2, boosted by 2.3 times than Pt/C–IrO2. Two constructed ZABs efficiently power the NRR‐OER system to electrochemically generate ammonia implying its superior trifunctionality. [ABSTRACT FROM AUTHOR]

Metal sulfides are promising alternatives to noble metal electrocatalysts for water‐based hydrogen evolution. Pentlandites, notably, exhibit high activity in acidic environments. To explore their potential in alkaline conditions, pentlandite electrodes are tested in both conventional three‐electrode setups and scaled up to a 12.6 cm2$^{2}$ membrane electrode assembly (MEA). Optimized pentlandites with a stochiometry of M9S8$\left(\text{M}\right)_{9} \left(\text{S}\right)_{8}$, containing Fe, Ni, and Co, show reduced overpotentials for hydrogen evolution with higher Fe and Ni contents. However, a minimum Co content of three equivalents is necessary for peak hydrogen evolution reaction activity with −0.40 V versus reversible hydrogen electrode at −300 mA cm−2$^{- 2}$. Stability assessments via X‐ray photoelectron and Raman spectroscopy reveal minor surface changes for Fe and Ni species but significant leaching of cobalt from Co4.5$_{4.5}$Ni4.5$_{4.5}$S8$_{8}$ surfaces postelectrolysis. Selected pentlandite catalysts are integrated into MEAs, with Fe4Co3Ni2S8$\left(\text{Fe}\right)_{4} \left(\text{Co}\right)_{3} \left(\text{Ni}\right)_{2} \left(\text{S}\right)_{8}$ achieving 1 A cm−2$^{- 2}$ at 2.2 V with minimal potential decay of 50 μV h−1$^{- 1}$ alongside a La0.8$_{0.8}$Sr0.2$_{0.2}$CoO3$_{3}$ anode. These findings underscore the suitability of pentlandite catalysts for water splitting at industrial scales under alkaline conditions. [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]

Abstract: The urine albumin (Alb)-to-creatinine (Crn) ratio (UACR) is a sensitive and early indicator of chronic kidney disease (CKD) and cardiorenal syndrome. This study developed a portable and wireless electrochemical-sensing platform for the sensitive and accurate determination of UACR. The developed platform consists of a carbon nanotube (CNT)-2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)(ABTS)-based modified UACR sensor, a miniaturised potentiostat, a cup holder embedded with a magnetic stirrer and a smartphone app. The UACR sensing electrode is composed of two screen-printed carbon working electrodes, one screen-printed carbon counter electrode and a screen-printed AgCl reference electrode. The miniaturised potentiostat, which is controlled by the developed app, performs cyclic voltammetry and amperometry to detect Alb and Crn, respectively. Clinical trials of the proposed system by using spot urine samples from 30 diabetic patients indicate that it can accurately classify all three CKD risk statuses within 30 min. The high accuracy of our proposed sensing system exhibits satisfactory agreement with the commercial biochemical analyser TBA-25FR (Y = 0.999X, R2 = 0.995). The proposed UACR sensing system offers a convenient, reliable and affordable solution for personal mobile health monitoring and point-of-care urinalysis. [ABSTRACT FROM AUTHOR]

Special flower rod-shaped Ag 2.69% /Cu 2 Se nanowires (NWs) electrocatalytic composites were prepared. Ag 2.69% /Cu 2 Se NWs composites exhibit excellent electrocatalytic CO 2 reduction to ethanol (70.1 %). Metallic silver (Ag) nanoparticles (NPs) modulated the electronic structure of the catalyst to achieve a high enrichment of Cuδ+ (0 < δ < 1), which promoted C C coupling. [Display omitted] Electrocatalytic carbon dioxide reduction reaction (eCO 2 RR) is one of the attractive approaches to CO 2 utilization. Nevertheless, it remains a challenge to prepare highly efficient and selective electrocatalysts to realize deep conversion of multi-carbon products. The absence of active sites due to the reconfiguration of copper-based catalysts leads to migration deactivation during catalysis, rendering low catalytic efficiency. In this work, Cu 2 Se nanowires (NWs) were obtained from the Cu foam. After further electroreduction for 90 s, Ag nanoparticles (NPs) were modified on the flower rod-shaped Cu 2 Se NWs (Ag 2.69% /Cu 2 Se NWs). This interfacial modification strategy, balanced the Cuδ+ active valence state on the surface of the Ag 2.69% /Cu 2 Se NWs, led to a high Faradaic efficiency (FE) of ethanol (∼70 %) at −0.52 V (vs. reversible hydrogen electrode (RHE)). Besides, the Ag 2.69% /Cu 2 Se NWs achieved a high partial current (∼13.9 mA) for ethanol, 18.5 μmol/h ethanol yield and an energy efficiency of 47.1 % in the H-type electrolytic cell. The reaction mechanism was investigated at the molecular level through density functional theory (DFT) calculation. The interface-modified Ag NPs provided stable *COOH intermediates during the reaction process, effectively achieving surface *CO enrichment. Besides, the presence of Ag NPs resulted in the generation of abundant Cuδ+ active species. The *CO migrated to the Cuδ+ active sites to accelerate the asymmetric coupling of *CO and *CHO, which significantly improved the FE of CO 2 electroreduction to ethanol. Our work offers a promising approach for designing Cu 2 Se-based nanowires electrocatalysts for CO 2 reduction with excellent activity and selectivity. [ABSTRACT FROM AUTHOR]

The present work exhibits an efficient strategy to adjust the electron structure of Bi/Bi 2 O 3 -In 2 O 3 @C by the synergistic effects of Bi-In hetero-diatoms and nanoheterostructure. Also, the formed hetero-bridging absorption of *OCHO and d-d orbital coupling effect could regulate the d-band center and improve the DOS around E f , moderating the free energy of intermediates. Thus, the enhance ECO 2 RR performance can be observed. [Display omitted] Electrocatalytic CO 2 reduction reaction (ECO 2 RR) to value-added chemicals is of significant importance to control CO 2 emission and reach carbon neutrality. Herein, Bi/Bi 2 O 3 -In 2 O 3 @C electrocatalyst with nanosheet arrays is successfully fabricated by a facile solvothermal with subsequent calcination process. It is found that the electron structure of Bi/Bi 2 O 3 -In 2 O 3 @C can be adjusted by the synergistic effects of Bi-In hetero-diatoms, which can significantly enhance its inherent catalytic activity. As expected, it requires a maximum HCOOH faradaic efficiency (FE HCOOH) of 97.6 % at −1.1 V vs. Reversible Hydrogen Electrode (RHE), which further delivers over 90 % at a wide potential range of −0.8 to −1.4 V vs. RHE, and exhibits high stability of 90.1 % over 60-h long-term test. In-situ Raman analysis is performed to explore the mechanism of its excellent stability. Meanwhile, in-situ attenuated total reflection-Fourier-transform infrared (ATR-FTIR) analysis combined with theoretical calculations reveal that the hetero-bridging absorption of *OCHO and d-d orbital coupling effect can regulate d-band center of Bi/Bi 2 O 3 -In 2 O 3 @C and improve its density of states around E f , moderating free energy of intermediates, thereby the improved formate production performance can be seen. [ABSTRACT FROM AUTHOR]

[Display omitted] • The performance and stability of different anionic salts in 2G for HC/Na half-cells are investigated. • The interfacial chemistry, interphasial properties and electrochemical kinetics are comprehensively studies. • The underlying side reaction and mechanism of different anionic salts with Na metal is elucidated. In hard carbon (HC) anodes, elucidating the relationship between the solid electrolyte interphase formation and the solvated Na+ co-intercalation mechanism is crucial, particularly considering different anionic salts in ether-based electrolytes. Here, we comprehensively explore the impact of different anionic salts on the electrochemical performance of HC/Na half-cell and elucidate the underlying mechanism through experimental studies and theoretical calculations. The surface morphology of the HC anode and its interphasial property are further investigated to evaluate the differences endowed by the presence of various anionic salts in diglyme (2G). The HC/Na half-cells with NaPF 6 -2G and sodium trifluoromethanesulfonate (NaCF 3 SO 3)-2G display superior electrochemical performance with faster kinetics and lower interfacial resistance than those with NaClO 4 -2G, sodium bis-(fluorosulfonyl) imide (NaFSI)-2G and sodium bis-(trifluoromethanesulfonyl) imide (NaTFSI)-2G. NaClO 4 -2G forms a relatively thick interphase layer with high resistance at the electrode/electrolyte interface owing to its insufficient stability. NaFSI-2G and NaTFSI-2G exhibit severe side reactions with Na metal, producing a thick interphase layer on the HC surface with high interfacial resistance from excess electrolyte decomposition, thus deteriorating the electrochemical performance. In summary, the study on the stability of different anionic salts in ether-based electrolyte for the HC anode with the intercalation mechanism provides valuable insights for screening appropriate conductive salts for high-performance sodium-ion batteries, especially when considering Na metal counter/reference electrodes. [ABSTRACT FROM AUTHOR]

[Display omitted] The production of hydrogen gas as an environmentally friendly and emission-free fuel source, has emerged as the preeminent substitute for traditional fossil fuels. The demand for a viable and low-cost substitute of the anodic Oxygen Evolution Reaction (OER) in hydrogen gas production has led researchers to explore the Hydrazine Oxidation Reaction (HzOR), aiming to reduce overpotential. In this study, we present the synthesis of a NiSeP@NiCo/Cu electrocatalyst via electrodeposition method, offering precise control over parameter adjustments and an affordable price. The binder-free nanosheet structure of this electrocatalyst demonstrates improved performance in water electrolysis, resulting in potentials of −40 and −134 mV vs. Reversible Hydrogen Electrode (RHE) for Hydrogen Evolution Reaction (HER) and 0.041 and 0.194 V (vs. RHE) for HzOR (i = 10 and 100 mA.cm−2). The electrode has excellent features, including active electrochemical surface, synergistic effects among the elements, high stability, super-hydrophilicity and super-aerophobicity. The Bi-functional performance of electrode was tested in a two-electrode set for HER/HzOR, the cell voltage required to reach current densities of 10 and 100 mA.cm−2 were determined as 0.071 and 0.298 V respectively. On the whole, this work presents the excellent capabilities of the synthesized electrode (NiSeP@NiCo/Cu) for hydrogen gas production. [ABSTRACT FROM AUTHOR]

InBiO 6 catalyst is employed for the electroreduction of CO 2. In 2 O 3 /Bi 2 O 3 interface effects exhibit low negative potential and high formate Faradaic efficiency. The study described presents an effective approach for developing high-performance CO 2 reduction electrocatalysts derived from metal-organic frameworks. [Display omitted] • InBiO 6 two-phase co-existing composites was designed for CO 2 electroreduction. • High FE formate (>80 %) in a wide potential window (−0.76 ∼ −1.26 V vs. RHE). • Long-term stability of 317h in H-type cell. • The introduction of Bi changes the electronic environment around In and activates the In sites. • DFT calculations reveal that the heterostructure benefit formate production. The electrochemical reduction of CO 2 (ERCO 2) has emerged as one of the most promising methods for achieving both renewable energy storage and CO 2 recovery. However, achieving both high selectivity and stability of catalysts remains a significant challenge. To address this challenge, this study investigated the selective synthesis of formate via ERCO 2 at the interface of In 2 O 3 and Bi 2 O 3 in the InBiO 6 composite material. Moreover, InBiO 6 was synthesized using indium-based metal–organic frameworks as precursor, which underwent continuous processing through ion exchange and thermal reduction. The results revealed that the formate Faradaic efficiency (FE formate) of InBiO 6 reached nearly 100 % at −0.86 V vs. reversible hydrogen electrode (RHE) and remained above 90 % after continuous 317-h electrolysis, which exceeded those of previously reported indium-based catalysts. Additionally, the InBiO 6 composite material exhibited an FE formate exceeding 80 % across a wide potential range of 500 mV from −0.76 to −1.26 V vs. RHE. Density-functional theory analysis confirmed that the heterogeneous interface of InBiO 6 played a role in achieving optimal free energies for *OCHO on its surface. Furthermore, the addition of Bi to the InBiO 6 matrix facilitated electron transfer and altered the electronic structure of In 2 O 3 , thereby enhancing the adsorption, decomposition, and formate production of *OCHO. [ABSTRACT FROM AUTHOR]

Si in Bi silicates changes the electronic structure of Bi in terms of weakening and elongating the Bi-O bond, and strengthening the electron transfer from Bi to CO 2 , thereby promoting the generation of CO 2 *− and *OCHO intermediates and boosting HCOOH production. [Display omitted] • CNT@Bi silicates exhibits outstanding CO 2 RR selectivity to produce formate. • The role of Si is revealed via In situ ATR-SEIRAS measurement, XPS, and DFT calculations. • Si weakens Bi-O bond, strengthens electron transfer from Bi to CO 2 , and promotes CO 2 adsorption and activation. • CNTs transfers electrons to Bi silicates thereby increasing conductivity and oxygen vacancy. • The designed structure endows the highest electrochemical activation area. Electrochemical CO 2 reduction reaction (CO 2 RR) is one of the most attractive measures to achieve the carbon neutral goal by converting CO 2 into high-value chemicals such as formate. Si in Bi silicates is promising to enhance CO 2 adsorption and activation due to its strong oxygenophilicity. Whereas, its role in boosting CO 2 RR via the cheap Bi-based catalysts is still not clear. Herein, we design CNT@Bi silicates catalyst, demonstrating the highest FE HCOOH of 96.3 % at −0.9 V vs. reversible hydrogen electrode with good stability. Through X-ray photoelectron spectroscopy (XPS), in-situ Attenuated Total Reflectance-Fourier Transform Infrared (In-situ ATR-SEIRAS) experiments, and Density Functional Theory (DFT) calculations, the role of Si in Bi silicates was unveiled: tuning the electronic structure of Bi, weakening the Bi-O bond, and strengthening electron transfer from Bi to CO 2 , thereby promoting the generation of CO 2 *− and *OCHO intermediates. Additionally, carbon nanotubes (CNTs) promote not only the conductivity but also the generation of abundant oxygen vacancies in CNT@Bi silicates evidenced by the electron transfer from CNT to Bi silicates from XPS results. Further, the CNT@Bi silicates endows it with the highest electrochemical activation area. These findings suggest the effectiveness of Si in Bi silicates and structure tuning to design highly selective CO 2 RR catalyst for HCOOH production. [ABSTRACT FROM AUTHOR]

[Display omitted] Electrocatalytic nitrate reduction reaction presents a promising avenue for environmentally friendly ammonia (NH 3) synthesis and wastewater treatment. An essential aspect to consider is the meticulous design of electrocatalysts. This study explores the utilization of a Ni-Co alloy nanosheet-decorated three-dimensional titanium dioxide (3D-TiO 2) nanobelts electrodeposited on titanium meshes (Ni x Co y @TiO 2 /TM) for efficient electrocatalytic NH 3 production. The optimized Ni 1 Co 3 @TiO 2 /TM electrode achieves a significant NH 3 yield of 676.3 ± 27.1 umol h−1 cm−2 with an impressive Faradaic efficiency (FE) of 95.1 % ± 2.1 % in a 0.1 M KOH solution containing 0.1 M NO 3 − at −0.4 V versus the reversible hydrogen electrode. Additionally, the electrode demonstrates exceptional electrochemical activity for NH 3 synthesis in simulated wastewater, delivering an outstanding NH 3 yield of 751.6 ± 44.3 umol h−1 cm−2 with a FE of 96.8 % ± 0.4 % at the same potential of −0.4 V. Moreover, the electrode exhibits minimal variation in current density, NH 3 yields and FEs throughout the 24-h stability test and the 20-cycle test, demonstrating its excellent stability and durability. This study offers a straightforward electrodeposited approach for the development of 3D-nanostructured alloys as catalysts for NH 3 electrosynthesis from nitrates at room temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] The recombination of photogenerated electron-hole pairs of the photoanode seriously impairs the application of bismuth vanadate (BiVO 4) in photoelectrochemical water splitting. To address this issue, we prepared a Yb:BiVO 4 /Co 3 O 4 /FeOOH composite photoanode by employing drop-casting and soaking methods to attach Co 3 O 4 /FeOOH cocatalysts to the surface of ytterbium-doped BiVO 4. The prepared Yb:BiVO 4 /Co 3 O 4 /FeOOH photoanode demonstrates a high photocurrent density of 4.89 mA cm−2 at 1.23 V versus the reversible hydrogen electrode (RHE), which is 5.1 times that of bare BiVO 4 (0.95 mA cm−2). Detailed characterization and testing demonstrated that Yb doping narrows the band gap and significantly enhances the carrier density. Furthermore, Co 3 O 4 serves as a hole transfer layer to expedite hole migration and diminish recombination, while FeOOH offers additional active sites and minimizes surface trap states, thus boosting stability. The synergistic effects of Yb doping and Co 3 O 4 /FeOOH cocatalyst significantly improved the reaction kinetics and overall performance of PEC water oxidation. This work provides a strategy for designing efficient photoanodes for PEC water oxidation. [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]

The chiral-induced spin selectivity (CISS) effect offers promising prospects for spintronics, yet designing chiral materials that enable efficient spin-polarized electron transport remains challenging. Here, we report the utility of covalent organic frameworks (COFs) in manipulating electron spin for spin-dependent catalysis via CISS. This enables us to design and synthesize three three-dimensional chiral COFs (CCOFs) with tunable electroactivity and spin-electron conductivity through imine condensations of enantiopure 1,1′-binaphthol-derived tetraaldehyde and tetraamines derived from 1,4-benzenediamine, pyrene, or tetrathiafulvalene skeletons. The CISS effect of CCOFs is verified by magnetic conductive atomic force microscopy. Compared with their achiral analogs, these CCOFs serve as efficient spin filters, reducing the overpotential of oxygen evolution and improving the Tafel slope. Particularly, the diarylamine-based CCOF showed a low overpotential of 430 mV (vs reversible hydrogen electrode) at 10 mA cm−2 with long-term stability comparable to the commercial RuO2. This enhanced spin-dependent OER activity stems from its excellent redox-activity, good electron conductivity and effective suppression effect on the formation of H2O2 byproducts. [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]

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]

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]

The present work utilizes Direct Laser Interference Patterning (DLIP) to impart periodic microstructures onto the surface of nickel foils. A pulsed laser source emitting green radiation (514 nm) with pulse duration between 282 fs and 1 ps is utilized to produce line and cross-like pattern geometries having a spatial period of 3.0 µm and a maximum structure depth of ~ 2.8 µm. Both the pulse duration and number of consecutive scans are varied in order to assess their influence on the structure formation. Afterwards, the treated Ni- electrodes are used for alkaline water electrolysis. The most active electrode exhibits an overpotential of -227 mV at a current density of -0.5 A cm-2 for the Hydrogen Evolution Reaction (HER). Thus, the technique here proposed permitted a 51 % reduction in the overpotential of the HER compared to the untreated Ni-electrode, opening up possibilities for the development of more efficient electrodes for hydrogen production. [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]