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We present a fabrication process for hierarchical (Ni,Co)0.85Se sheets, achieving efficient oxygen evolution reaction (OER) activity with a 10 mA cm−2 current density at an overpotential of 290 mV. Porous architecture and doping improve kinetics, supported by DFT calculations. This approach offers insights into designing stable, high-performance OER catalysts. [ABSTRACT FROM AUTHOR]

The activity and stability of a heterogeneous water oxidation catalyst inspired by the Photosystem II – Oxygen Evolving Center (PSII-OEC) is reported. Ca-doped birnessite MnOx supported on a liquid crystalline reduced graphene oxide (LCrGO) substrate exhibited unprecedented performance for an abiological catalyst at pH 7, including an exceedingly low onset overpotential of 0.52 V (vs. 0.48 V reported for the PSII-OEC, 0.75 V for Pt, and 0.72 V for birnesite MnOx) and remarkably high activity per unit area at 0.56 V overpotential (∼10% that of a hypothetical, closely-packed monolayer of OEC sites at their optimum density of 1014 sites per cm2). [ABSTRACT FROM AUTHOR]

Developing efficient electrocatalyst in sulfides for hydrogen evolution reaction (HER) still poses challenges due to the lack of understanding the role of sulfide heterointerface. Here, we report a sulfide heterostructure RuSx/NbS2, which is composed of 3R‐type NbS2 loaded by amorphous RuSx nanoparticles with S−S bonds formed at the interface. As HER electrocatalyst, the RuSx/NbS2 shows remarkable low overpotential of 38 mV to drive a current density of 10 mA cm−2 in acid, and also low Tafel slope of 51.05 mV dec−1. The intrinsic activity of RuSx/NbS2 is much higher than that of Ru/NbS2 reference as well as the commercial Pt/C. Both experiments and theoretical calculations unveil a reversed charge transfer at the interface from NbS2 to RuSx that driven by the formation of S−S bonds, resulting in electron‐rich Ru configuration for strong hydrogen adsorption. Meanwhile, electronic redistribution induced by the sulfide heterostructure facilitates hydrogen spillover (HSo) effect in this system, leading to accelerated hydrogen desorption at the basal plane of NbS2. This study provides an effective S−S bond strategy in sulfide heterostructure to synergistically modulate the charge transfer and adsorption thermodynamics, which is very valuable for the development of efficient electrocatalysts in practical applications. [ABSTRACT FROM AUTHOR]

The exploration of bifunctional electrocatalysts with abundant resources and excellent catalytic performances is currently one of the fundamental conditions for the development and promotion of hydrogen energy technology. In this work, an extremely simple one-step hydrothermal strategy was proposed for the preparation of CoFe-layered double hydroxide nanosheets intercalated with molybdate (CoFe-LDH-MoO 4 2-). The well-designed electrocatalyst exhibits outstanding catalytic activity due to the adjustability of two-dimensional layered materials, synergistic effects of Co and Fe, as well as expanded inter-layer distance, which necessitates overpotential of 74 and 92 mV at 10 mA cm−2 for HER and OER, respectively. When the CoFe-LDH-MoO 4 2- is assembled in a two-electrode system, it requires a cell voltage of 1.50 V to drive 10 mA cm−2. The innovative exploration of this work offers a novel approach to construct multifunctional electrocatalysts for efficient and stable total water splitting. • A intercalation strategy is proposed to construct CoFe-LDH-MoO 4 2-. • CoFe-LDH-MoO 4 2- exhibits excellent overall water spitting performancesater splitting performance. • The enhanced electrocatalytical activity is due to the expanded interlayer distances. [ABSTRACT FROM AUTHOR]

The development of electricity‐driven oxygen evolution reaction (OER) is a potent solution for energy storage applications. In recent years, there is a surge in interest in designing transition metal‐based catalysts with stable linkages, presenting an efficient alternative to noble metal‐based electrocatalysts. Transition metal complexes linked by salen ligands garner considerable attention due to their capacity to chelate and stabilize metal ions. This work presents a novel approach by strategically incorporating the metal–salen core into a porous organic polymer (POP) backbone, thereby fabricating a highly effective electrocatalyst for oxygen evolution. The judicious selection of metal–salen active sites, coupled with the intramolecular free volume (IMFV) of the triptycene core and the high specific surface area of the salen–POPs, result in superior OER activity. By precisely tuning the structure through variation of the transition metal in the salen unit, deep insights are gained into their electrocatalytic behavior. Notably, the most efficient catalyst, Ni‐DHDA‐TAT, exhibits an impressively low overpotential (η10) of ≈ 270 mV at a current density of 10 mA cm−2 for OER (in 1 m KOH). Further, Ni‐DHDA‐TAT retains its activity even after 50 h of chronoamperometry and 1000 cyclic voltammetry cycles with negligible degradation in its initial performance. [ABSTRACT FROM AUTHOR]

The discovery of a cutting-edged electrocatalyst for water-splitting is an immense challenge to developing metal–air batteries and fuel cells. Therefore, developing sophisticated electrocatalysts with high activity and stability based on non-noble metal elements remains a great challenge. Herein, we prepared efficient polyhedral Ni/Cu bimetallic MOFs that are synthesized by a simple solvothermal method, in which the incorporation of Ni enhances the electrocatalytic properties of CuBTC MOF with distinct molar ratios. Benefiting from the unique morphology, and the favourable effect of Ni incorporation, the polyhedral Ni/Cu bimetallic MOFs exhibit conspicuous efficiency towards OER. The optimized NiCuBTC (2 : 8) bimetallic MOF exhibited superior activity with an overpotential of 290 mV to reach the current density of 10 mA cm−2. Moreover, the NiCuBTC (2 : 8) MOF also shows better long-term stability. The present work shows a facile strategy to design and synthesize a NiCuBTC (2 : 8) MOF electrocatalyst, which offers superior electrocatalytic performance towards water electrocatalysis. [ABSTRACT FROM AUTHOR]

Engineering metal‐oxygen (M‒O) interactions for catalyzing oxygen evolution reaction (OER) by tuning the coordination geometry of metal sites is crucial for improving catalytic performance, which remains unexplored, especially in structurally diverse phosphate‐based catalysts. Herein, two NaCoPO4 (NCP) polymorphs with distinct metal coordinations: orthorhombic‐Pnma (CoO6) and hexagonal‐P65 (CoO4) denoted as O‐NCP and H‐NCP, respectively are synthesized through unique quenching‐based synthesis, to investigate the impact of coordination geometry on M‒O covalency and OER performance. The CoO4 (H‐NCP) polymorph delivered superior OER activity with low overpotential at 10 mA cm−2 (η10 = 303 mV) and long‐term stability than CoO6‐based O‐NCP. Spectroscopic and computational studies linked the superior activity of CoO4 to higher Co‒O covalency, enhanced metal electronic states near the Fermi level, and improved electrochemical reconstruction. Further, M‒O covalency regulated OER mechanism, where high‐covalent CoO4 follows conventional concerted proton‐electron transfer pathway, while CoO6 entails a non‐concerted pathway, where the lattice oxygen participation remains unfavorable due to downshifted O 2p band center. Further, OER‐active tetrahedral metal is demonstrated in a high‐entropy catalyst requiring lower η10 of ≈284 mV. This study unlocks a unique strategy for designing next‐generation OER catalysts with superior activity and durability, harnessing the interplay between metal coordination and metal‐oxygen covalency. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A novel electrocatalyst, Ni‐Co/β‐Mo2C@C, was rationally designed to enhance the efficiency of the hydrogen evolution reaction (HER) in this work. Assembled with two‐dimensional Ni‐Co nanosheets onto Mo2C nanorods coated with a thin carbon shell, the catalyst demonstrates remarkable performance, including low overpotential (η10 = 57 mV) and reduced Tafel slope (63 mV·dec–1) in 0.5 mol·L–1 H2SO4 electrolyte. This innovative design strategy provides abundant active sites and efficient electron/ion transport pathways, effectively shortening reactant diffusion distances and enhancing electrocatalytic activity. Additionally, the carbon shell coating protects the catalyst from etching and agglomeration, ensuring its durability. This work presents a promising approach for engineering highly efficient metal carbide‐based HER catalysts through tailored composition and nanostructure design. [ABSTRACT FROM AUTHOR]

Heterogeneous dual‐site electrocatalysts are emerging cutting‐edge materials for efficient electrochemical water splitting. However, the corresponding oxygen evolution reaction (OER) mechanism on these materials is still unclear. Herein, based on a series of in situ spectroscopy experiments and density function theory (DFT) calculations, a new heterogeneous dual‐site O−O bridging mechanism (DSBM) is proposed. This mechanism is to elucidate the sequential appearance of dual active sites through in situ construction (hybrid ions undergo reconstruction initially), determine the crucial role of hybrid dual sites in this mechanism (with Ni sites preferentially adsorbing hydroxyls for catalysis followed by proton removal at Fe sites), assess the impact of O−O bond formation on the activation state of water (inducing orderliness of activated water), and investigate the universality (with Co doping in Ni(P4O11)). Under the guidance of this mechanism, with Fe−Ni(P4O11) as pre‐catalyst, the in situ formed Fe−Ni(OH)2 electrocatalyst has reached a record‐low overpotential of 156.4 mV at current density of 18.0 mA cm−2. Successfully constructed Fe−Ni(P4O11)/Ti uplifting the overall efficacy of the phosphate from moderate to superior, positioning it as an innovative and highly proficient electrocatalyst for OER. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A novel electrocatalyst, Ni‐Co/β‐Mo2C@C, was rationally designed to enhance the efficiency of the hydrogen evolution reaction (HER) in this work. Assembled with two‐dimensional Ni‐Co nanosheets onto Mo2C nanorods coated with a thin carbon shell, the catalyst demonstrates remarkable performance, including low overpotential (η10 = 57 mV) and reduced Tafel slope (63 mV·dec–1) in 0.5 mol·L–1 H2SO4 electrolyte. This innovative design strategy provides abundant active sites and efficient electron/ion transport pathways, effectively shortening reactant diffusion distances and enhancing electrocatalytic activity. Additionally, the carbon shell coating protects the catalyst from etching and agglomeration, ensuring its durability. This work presents a promising approach for engineering highly efficient metal carbide‐based HER catalysts through tailored composition and nanostructure design. [ABSTRACT FROM AUTHOR]

Lithium sulfide (Li2S) is a promising electrode material with high specific capacity and can be paired with commercial anode materials such as graphite. However, bulk Li2S requires a high activation energy during the initial charge due to its inert electrochemical activity, resulting in high charge overpotential. Here, lithium phenyl selenide (PhSeLi) is proposed as a mediator that can effectively activate Li2S by altering the oxidation pathway in the initial charge process. It enables Li2S to release normal capacity over the general voltage range (1.5–3 V). The composite cathode with the Li2S:PhSeLi molar ratio of 4:1 exhibits a high reversible capacity of 615.9 mAh g−1 at 0.2 A g−1 after 400 cycles in all‐solid‐state batteries with Li7P3S11 sulfide electrolyte and In–Li anode (the corresponding capacity based on Li2S is 1016.6 mAh g−1). In a full cell with a partially pre‐lithiated silicon anode, it can still provide an average discharge capacity of 524 mAh g−1 at 0.1 A g−1 (the capacity based on Li2S is 844.2 mAh g−1). This work will contribute to the further development of Li2S‐based all‐solid‐state Li–S batteries. [ABSTRACT FROM AUTHOR]

Because of its low cost and abundant sources, hydrogen serves as a clean energy alternative capable of successfully substituting fossil fuels. A highly efficient method for generating hydrogen energy currently is by the electrolysis of water. The oxygen‐extraction reaction (OER), a component of water electrolysis, requires a complex chemical pathway that involves multiproton and multielectron interactions. To enhance reaction efficiency in the OER process, catalysts are crucial; thus, the search for high‐performance, cost‐effective catalysts is underway. This experimental study involved the enhancement of the five‐membered high‐entropy oxide (FeCoNiMnCu)3O3.2 by incorporating a sixth group element (Zn, Al). The organization, morphology, and OER properties were analyzed following the preparation utilizing a mechanical ball milling process. A series of rock salt‐type hexagonal high entropy oxides with differing ball milling durations were synthesized to investigate the influence of the production method on the surface shape and catalytic properties of high entropy oxides. The results indicated that the single‐phase rock salt structure of (FeCoNiMnCuAl)3O3.5, a high‐entropy oxide, exhibited significantly altered diffraction peaks, hence improving OER performance. Optimization of the preparation technique revealed that a 72‐h ball milling duration resulted in an overpotential of merely 293 mV and an electrochemically active surface area approximately double that of the other milling durations. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are selective electrocatalysts for oxygen evolution reactions (OER) owing to their high specific surface area, rich pore structure, and so on. Herein, a series of Fe/FeCo-based MOFs were developed over nickel foam (NH 2 -MIL-101-Fe@NF / NH 2 -MIL-101-(CoFe)@NF-X) employing a facile process. An overpotential of 376 mV was observed at 100 mA cm−2 for Fe-MOF. The structural modification with the addition of Co for FeCo-MOFs can improve the morphology as well as the electrochemical performance. Among of them, NH 2 -MIL-101-(CoFe)@NF-2 illuminates an excellent overpotential 329 mV with a small Tafel slope of 50 mV dec−1 at 100 mA cm−2. Its surface roughness facilitates the deep penetration of electrolyte to the internal structure of the electrode. Theoretical calculations confirmed the introduction of Co can reduce the overpotential from 0.68 V to 0.34 V at the rate-determining step (from O∗ to OOH∗). This is a key feature that promotes the electrochemical performance of OER catalysts. Improved electronic structures of Fe-based MOFs by the controllable introduction of Co, and the OER performance of NH 2 -MIL-101-(CoFe)@NF-2 was excellent, with an overpotential of 329 mV at 100 mA cm−2, which has exceeded that of most reported MOFs catalysts for electrocatalytic OER. [Display omitted] • A series of Fe/FeCo-based MOFs were in-situ grown on NF by a one-step method. • The doping of cobalt ions increases the number of exposed active sites. • NH 2 -MIL-101-(CoFe)@NF-2 only a small overpotential of 329 mV at 100 mA cm−2. • It exhibits excellent stability at the current density of 50 mA cm−2 for 28 h. • The DFT calculations further confirm the positive effect of Co. [ABSTRACT FROM AUTHOR]

Allotropy structures may induce different electronic and optical properties, which implies that one can acquire novel performance by screening its allotropy structures. Here, we demonstrate that two In 2 S 3 allotropy monolayers with excellent photocatalytic performance for water splitting to produce hydrogen are screened from 1038 In 2 S 3 allotropy monolayers. The phonon dispersions are calculated for 39 allotropes with the lowest formation energies, which confirms that 16 allotropes have dynamic stability, including the only one reported in the literature. The results of overpotentials of band edges demonstrate that 8 allotropes match the potential requirements of overall water splitting. The thermodynamic stability of these allotropes is further confirmed for the obtained allotropes. Then, two allotropes with maximum solar-to-hydrogen efficiency of 17.78% and 29.32% are screened. The Gibbs free energy with the solvent effect indicates that one allotrope can proceed photocatalytic hydrogen/oxygen evolution reactions spontaneously. Therefore, the newfound In 2 S 3 allotropy monolayers have potential applications in photocatalytic overall water splitting for hydrogen generation. [Display omitted] • 8 In 2 S 3 monolayers for photocatalytic HER/OER are screened from 1038 allotropes. • The maximum η STH ′ of 29.32% is attributed to the In 2 S 3 -VIII monolayer. • Photocatalytic HER/OER can spontaneously proceed with In 2 S 3 -VI/VIII monolayers. • η STH ′ of In 2 S 3 -VI monolayer can be boosted from 17.78% to 30.16% by adjusting pH. [ABSTRACT FROM AUTHOR]

Quaternary layered double hydroxides (LDHs) are emerging as effective oxygen evolution reaction (OER) electrocatalysts for alkaline water splitting. In this work, NiCoMnFe-LDH has been successfully fabricated using leachate from recycled battery cathodes, demonstrating a sustainable approach to resource utilization. By incorporating varying amounts of Vulcan XC72 carbon as a support, we improved the conductivity of the NiCoMnFe-LDH. Our results indicate that the addition of Vulcan XC72 enhances the electrocatalytic performance of the nanocomposites. Notably, the NiCoMnFe-LDH/C-50 sample exhibited superior OER activity, with an overpotential of 329 ± 10 mV at a current density of 10 mA cm⁻2 and stable performance over 15 h. Detailed characterization confirmed the advantages of the carbon support in improving both the structural stability and catalytic efficiency. This work may pave the way to a sustainable method for repurposing spent battery cathodes, advancing the development of cost-effective and environmentally friendly electrocatalysts for clean energy applications. [Display omitted] • NiCoMnFe-LDH has been successfully extracted from spent battery materials. • Carbon support improved the electrochemical properties of NiCoMnFe-LDH. • NiCoMnFe-LDH/C nanocomposites showed high specific surface area. • NiCoMnFe-LDH/C-50 resulted in a low overpotential of 329 ± 10 mV. [ABSTRACT FROM AUTHOR]

Several strategies have been adopted to enhance the electrochemical features of metal-organic framework structures for water splitting, however, a suitable conditions can effectively boost the electrocatalytic activity. Herein, molybdenum-based zeolite imidazolate frameworks (Mo 2g ZIF-67 and Mo 4g ZIF-67) have been synthesized by solvothermal process and electrocatalytic activity was examined at various elevating temperatures of 1 M KOH electrolyte. Mo 4g ZIF-67 nanorods showed the overpotential (η 10) of 358 mV at 20 °C, which was improved to 221 mV at 80 °C for the oxygen evolution reaction. Mo 4g ZIF-67 nanorods exhibited the Tafel slope of 77 mV dec−1 at 80 °C and followed the Volmer-Heyrovsky mechanism. LSV curves reveal that Mo 4g ZIF-67 nanorods showed a greater current density and a good turnover frequency (TOF) of 221.0 ms−1 at the fixed V RHE of 0.7 V. Similarly, Mo 4g ZIF-67 nanorods revealed the η 10 of 181 and 93 mV at 20 and 80 °C, respectively for the HER process. Mo 4g ZIF-67 nanorods displayed a Tafel slope of 95 mV dec−1 and TOF of 213.50 ms−1. The enhanced electrocatalytic activity may be due to rising temperatures, enhanced electrical conductivity at rising temperatures, well defined nanorods shape and greater ECSA, which provided the active sites and facile the flow of charge carriers for oxygen and hydrogen evolution reaction. The electrocatalyst, Mo 4g ZIF-67 nanorods exhibited a uniform current density during stability tests for 30 h at 20 °C, which was increased at 80 °C. Temperature elevation remarkably enhanced the HER and OER characteristics of the Mo 4g ZIF-67 nanorods and suggested an effective electrocatalyst for water splitting. • Mo 4 gZIF-67 nanorods have been synthesized by solvothermal treatment. • Mo 4g ZIF-67 nanorods showed the η 10 of 221 mV at 80 °C for the OER process. • Mo 4g ZIF-67 nanorods exhibited a Tafel slope of 77 mV dec−1 at 80 °C for OER process. • Mo 4g ZIF-67 nanorods exposed the η 10 of 93 mV at 80 °C for the HER process. • Mo 4g ZIF-67 nanorods displayed a TOF of 213.50 ms−1. [ABSTRACT FROM AUTHOR]

Because of its low cost and abundant sources, hydrogen serves as a clean energy alternative capable of successfully substituting fossil fuels. A highly efficient method for generating hydrogen energy currently is by the electrolysis of water. The oxygen‐extraction reaction (OER), a component of water electrolysis, requires a complex chemical pathway that involves multiproton and multielectron interactions. To enhance reaction efficiency in the OER process, catalysts are crucial; thus, the search for high‐performance, cost‐effective catalysts is underway. This experimental study involved the enhancement of the five‐membered high‐entropy oxide (FeCoNiMnCu)3O3.2 by incorporating a sixth group element (Zn, Al). The organization, morphology, and OER properties were analyzed following the preparation utilizing a mechanical ball milling process. A series of rock salt‐type hexagonal high entropy oxides with differing ball milling durations were synthesized to investigate the influence of the production method on the surface shape and catalytic properties of high entropy oxides. The results indicated that the single‐phase rock salt structure of (FeCoNiMnCuAl)3O3.5, a high‐entropy oxide, exhibited significantly altered diffraction peaks, hence improving OER performance. Optimization of the preparation technique revealed that a 72‐h ball milling duration resulted in an overpotential of merely 293 mV and an electrochemically active surface area approximately double that of the other milling durations. [ABSTRACT FROM AUTHOR]

Improvement of the catalytic performance of oxygen evolution reaction (OER) is the key to the large-scale implementation of water electrolysis. Here, we report an efficient strategy to improve the OER activity of Co-based nanocomposite catalysts by adding Fe3+ ions into the electrolyte. The overpotential of cobalt tartrate annealed at 700 °C can be decreased from 360 to 329 mV by introducing 20 ppm Fe3+ into the alkaline electrolyte. Electrochemical measurements indicate that the introduction of Fe3+ can generate more efficient active sites by cooperation with Co species and promote OER kinetics, thus improving electrocatalytic performance. [ABSTRACT FROM AUTHOR]

Densely packed IrOx‐ionomer agglomerates play a crucial role in the high mass transport resistance inside the anode catalyst layer (ACL), which in turn greatly affects the electrolysis performance at high current density. Therefore, agglomerate engineering for PEMWE is proposed in this work to enhance the oxygen transport process inside ACLs. Using self‐assembling nanotechnology, tightly packed primary aggregates are avoided and introduce the interconnected submicron pores and nanocavities into the catalyst‐ionomer agglomerate, confirmed by synchrotron radiation‐based nano‐CT, TEM, and BET. Such agglomerate engineering results in the enhancement of both dissolved oxygen and oxygen bubble transport inside the ACL confirmed by RDE tests and in‐situ bubble visualization. As a result, the mass transport overpotential is significantly reduced from 330 to 30 mV at 5 A cm−2 in PEMWE, optimized Ohmic resistance and catalyst utilization are also observed. Finally, high operating current density is achieved, i.e., 5 A cm−2 @2.04 V with Nafion 115 membrane and 7 A cm−2 @ 2.07 V with Nafion 212 membrane, under a low catalyst loading of 0.72 mgIr cm−2. This study proves the importance and feasibility of agglomerate engineering in further elevating the performance of PEMWE. [ABSTRACT FROM AUTHOR]

The potential of electrochemical water splitting to tackle energy and environmental issues has garnered substantial interest. In the present work, an effective ZnS/In2Te3 has been constructed by hydrothermal support on a stainless‐steel strip and explored for oxygen evolution. The addition of ZnS modifies the band structure of In2Te3 and enhances its specific conductivity and capacitance on an intrinsic level, making rapid ion transportation. The optimized ZnS/In2Te3 displayed efficient oxygen evolution reaction (OER) performance with an overpotential of 228 mV and a Tafel slope of 111 mV dec−1 with cyclic activity up to 1000 cycles in 1 M KOH solution. ZnS/In2Te3 has a large surface area (28 m3g−1) and a charge capacitance of (.037 mF), according to studies using Brunauer–Emmett–Teller and double‐layer capacitance. Combining several strategies improves overall electrochemical performance of ZnS/In2Te3, making it a promising option for use in state‐of‐the‐art OER. [ABSTRACT FROM AUTHOR]

Sodium‐oxygen batteries are emerging as new battery systems. Deep understanding of the origin of overpotential and the kinetic process in sodium‐oxygen batteries remain challenging yet critical. We apply a method of distribution of relaxation time (DRT) to decipher the electrochemical impedance spectroscopy (EIS), allowing us to monitor the changes of different kinetic processes during the discharging and charging. The origin of the overpotential in a battery was further comprehensively investigated combining DRT analysis with differential electrochemical mass spectrometry, Raman and other characterizations. Overpotential is found to primarily stem from oxygen mass transport during discharging, and from poor solid‐solid contact at the electrode surface during charging. Our work demonstrates the study of kinetic processes using DRT analysis, and suggests effective ways to improve the performances of sodium‐oxygen batteries. [ABSTRACT FROM AUTHOR]

Na metal batteries are regarded as an encouraging route for energy‐dense and low‐cost battery systems. However, the unstable and irreversible Na plating/stripping, caused by the uncontrolled dendritic Na growth, prevents their practical applications. Herein, a two‐dimensional sp2‐carbon‐linked covalent organic framework (cyano‐sp2c‐COF) is adopted as seeding/hosting coating layer for a highly stable interface with long cycling life, large capacity, and high Na utilization. Benefit from the features of a fully π‐conjugated structure and well‐defined cyano groups, cyano‐sp2c‐COF with superior sodiophilicity and small interface resistance can reduce the nucleation barrier, enable Na ion flux uniformity, and enhance interface stability. Ultimately, the system achieves a low nucleation overpotential of only 10 mV, a remarkable average Coulombic efficiency of 99.7% maintained over 500 cycles in half cells, and exceptional interfacial durability of 8500 h with a high accumulated capacity of 8.5 Ah cm−2 in symmetric cells. Furthermore, the symmetric cells also present a steady cycling, even increasing the depth of discharge up to 90%. As proof, full cells demonstrate a long lifespan enduring 2700 cycles with tiny capacity decay, providing valuable insights into the long‐life Na batteries. [ABSTRACT FROM AUTHOR]

Co-catalyst loading on photoelectrodes is considered to be an effective way to accelerate charge transfer. However, the bonding between most of the co-catalysts and photoelectrodes tends to be weak, which severely limits the role of co-catalysts in the catalytic system. Based on the above problems, we introduced trifluoroacetic acid (TFA) as a homogeneous molecular co-catalyst in the layered BiOIO 3 catalytic system for the first time. The BiOIO 3 -TFA photoelectrode exhibited excellent photoelectrochemical performance under light and applied bias voltage. The photocurrent density reached up to 0.228 μA cm−2, which was 2.11 times higher than that before modification, while the overpotential was negatively shifted by 183 mV. The results showed that the photogenerated electron-hole pairs in BiOIO 3 are excited and transferred to the TFA causing the C O double bond to break to form a TFA radical (TFA ·), which is then reduced to TFA - . This cyclic redox reaction accompanied by fast hole transfer can greatly reduce the recombination behavior during carrier transport. This work demonstrates a new form of co-catalyst for photoelectrochemical water splitting. Highly water-soluble molecules and TFA · /TFA - reversible reactions have considerable potential for the development of new co-catalysts. It also provides ideas for the establishment of new, efficient catalytic systems for inhibiting carrier recombination. [Display omitted] • A novel homogeneous TFA molecule was loaded on BiOIO 3 as a co-catalyst. • Reversible redox reaction of TFA · /TFA - accompanied by fast hole transfer. • TFA molecules can effectively suppress recombination during carrier transport. • BiOIO 3 -TFA photoelectrode exhibits excellent PEC performance under light and applied bias voltage. [ABSTRACT FROM AUTHOR]

The efficient and high-quality production for hydrogen through water electrolysis at high current densities is crucial for commercial utilization. However, the performance of existing hydrogen evolution reaction (HER) electrocatalysts is far from satisfactory. In this regard, we proposed a method to prepare Rh–Ni(OH) 2 catalyst based on Nickel foam (NF). The hydrolysis galvanic replacement of nickel boride with RhCl 3 led to produce a lattice contraction in Ni(OH) 2 due to the rigid pressure generated, resulting in outstanding HER performance at high current densities. It achieves an industrial current density of 500 mA cm−2 with an overpotential of 130 mV. Furthermore, at the industrially prefer temperature of 80 °C, only 67 mV overpotential is required. The catalyst also demonstrated exceptional stability, maintaining excellent performance even after a stability test of 100 days with a current density of 200 mA cm−2. Through Density-functional theory (DFT) calculations, Rh series reduced the hydrogen adsorption free energy. The electronic structure of Ni was improved by pretreatment with NaBH 4 , and then it reacted with Rh species, triggering the lattice contraction of Ni(OH) 2 , and the existence of this effect makes Rh play an active site role at the same time, and Ni also plays an auxiliary role in its role. The result is a highly efficient catalyst (Rh–Ni(OH) 2 /NF) for HER that achieves a current density of 500 mA cm−2 at only 130 mV and remains stable for three months under constant current conditions. [Display omitted] • Rh–Ni(OH) 2 on nickel foam boosts hydrogen production at high current densities. • Lattice contraction in Ni(OH) 2 due to Rh improves HER activity. • Achieves industrial current density with low overpotentials (130 mV at room temperature, 67 mV at 80 °C). • Exceptional Stability: Maintains performance even after a 3-month test. [ABSTRACT FROM AUTHOR]

Lattice strain engineering represents a cutting‐edge approach capable of delivering enhanced performance across various applications. The lattice strain can affect the performance of electrochemical catalysts by changing the binding energy between the surface‐active sites and intermediates. In this work, lattice strain is regulated through a homo/heterogeneous atomic interface merging. The strong lattice strain and electronic interactions between Ni and Mo facilitated the reaction kinetic of HER. The prepared NiMo@SSM exhibits excellent HER catalytic performance with 70 mV overpotential at the current density of 10 mA cm−2 and long‐term stability. The method of controlling lattice strain through hetero/homo atom interface merging provides a new strategy for designing high‐performance alkaline HER electrocatalysts. [ABSTRACT FROM AUTHOR]

The demand for renewable energy sources has become more urgent due to climate change and environmental pollution. The oxygen evolution reaction (OER) plays a crucial role in green energy sources. This article primarily explores the potential of using non‐noble metals, such as transition and rare earth metals, to enhance the efficiency of the OER process. Due to their cost‐effectiveness and unique electronic structure, these non‐noble metals could be a game‐changer in the field. ′Doping,′ which is the process of adding a small amount of impurity to a material to alter its properties, and ′synergistic effects,′ which refer to the combined effect of two or more elements that is greater than the sum of their individual effects, are two key concepts in this field. Transition and rare earth metals can reduce the overpotential, a measure of the excess potential required to drive a reaction, thus enhancing the OER process by engineering the electronic and surface molecular structure. This article summarizes the roles of various non‐noble metals in the OER process and highlights opportunities for researchers to propose innovative ways to optimize the OER process. [ABSTRACT FROM AUTHOR]

Here we present the density functional theory-based exploration of layered IrO2 polymorphs for the oxygen evolution reaction, as well as a data-driven geometric descriptor for catalytic activity. The layer edges are identified as promising active site motifs with not only low theoretical overpotential but also intriguing structural flexibility and to break the universal energetic scaling through torsional distortion. [ABSTRACT FROM AUTHOR]

Anode‐free Li‐metal battery (AFLMB) is being developed as the next generation of advanced energy storage devices. However, the low plating and stripping reversibility of Li on Cu foil prevents its widespread application. A promising avenue for further improvement is to enhance the lithophilicity of Cu foils and optimise their surfaces through a metal–organic framework (MOF) functional layer. However, excessive binder usage in the current approaches obscures the active plane of the MOF, severely limiting its performance. In response to this challenge, MOF polycrystalline membrane technology has been integrated into the field of AFLMB in this work. The dense and seamless HKUST‐1 polycrystalline membrane was deposited on Cu foil (HKUST‐1 M@Cu) via an epitaxial growth strategy. In contrast to traditional MOF functional layers, this binder‐free polycrystalline membrane fully exposes lithophilic sites, effectively reducing the nucleation overpotential and optimising the deposition quality of Li. Consequently, the Li plating layer becomes denser, eliminating the effects of dendrites. When coupled with LiFePO4 cathodes, the battery based on the HKUST‐1 membrane exhibits excellent rate performance and cycling stability, achieving a high reversible capacity of approximately 160 mAh g−1 and maintaining a capacity retention of 80.9 % after 1100 cycles. [ABSTRACT FROM AUTHOR]

The precise regulation of single‐atom catalysts (SACs) with the desired local chemical environment is vital to elucidate the relationship between the SACs structure and the catalytic performance. The debate on the effect of the local coordination environment is quite complicated even for the SACs with the same composition and chemical nature, calling for increased attention on the regulation of the second coordination shell. For oxide‐supported SACs, it remains a significant challenge to precisely manipulate the second coordination shell of single atoms supported on oxides due to the structural robustness of oxides. Here, Ir single atoms were anchored on NiO supports via different bonding strategies, resulting in the diverse Ir−O−Ni coordination numbers for Ir sites. Specifically, Ir1/NiO, Ir1−NiO, and Ir1@NiO SACs with increasing Ir−O−Ni coordination numbers of 3, 4, and 5 were synthesized, respectively. We found that the activity of the three samples towards oxygen evolution reaction (OER) exhibited a volcano‐shaped relationship with the Ir−O−Ni coordination number, with Ir1−NiO showing the lowest overpotential of 225 mV at 10 mA cm−2. Mechanism investigations indicate that the moderate coordination number of Ir−O−Ni in Ir1−NiO creates the higher occupied Ir dz2 orbital, weakening the adsorption strength for *OOH intermediates and thereby enhancing the OER activity. [ABSTRACT FROM AUTHOR]

Metal‐organic frameworks (MOFs) have emerged as promising pre‐catalysts for oxygen evolution reaction (OER) due to their marvelous structural reconstruction process in strongly alkaline media. However, targeting design MOF structures to achieve excellent OER performance of reconstructed products is a challenge. Here, a strategic defect engineering is used to promote the OER performance of reconstructed products. Briefly, modified linkers with monocarboxylic acids (ferrocene carboxylic acid, FcCA) are incorporated into MOF (NiBDC‐FcCA), leading to its stepwise reconstruction into Fe‐doped Ni(OH)2 and NiOOH during the OER process, with the oxygen vacancy and strategic doping of metal Fe persisting throughout the multi‐step reconstruction. Benefiting from the synergistic interaction of oxygen vacancies and Fe doping, NiBDC‐FcCA delivers the extremely enhanced current density at 1.6 V versus reversible hydrogen electrode by ≈9 times compared with that of NiBDC. Moreover, the optimized NiBDC‐FcCA/Fe foam exhibits excellent OER catalytic activity and stability with a low overpotential of 250 mV at 200 mA cm−2 and negligible activity decay after 1200 h at 1 A cm−2. Density function theory calculations reveal that Fe doping weakens the interaction of oxygen intermediate with Ni sites, favoring the formation of OOH* to accelerate the OER process. [ABSTRACT FROM AUTHOR]

A novel Ir−Mn dual‐atom electrocatalyst is synthesized by a facile ion‐exchange method by incorporating Ir in SrMnO3, which yields an extremely high activity and stability for the oxygen evolution reaction (OER). The ion exchange process occurs in a self‐limitation way, which favors the formation of Ir−Mn dual‐atom in the IrMnO9 unit. The incorporation of Ir modulates the electronic structure of both Ir and Mn, thereby resulting in a shorter distance of the Ir−Mn dual‐atom (2.41 Å) than the Mn−Mn dual‐atom (2.49 Å). The modulated Ir−Mn dual‐atom enables the same spin direction O (↑) of the adsorbed *O intermediates, thus facilitating the direct coupling of the two adsorbed *O intermediates to release O2 via the oxygen‐oxygen radical coupling mechanism. Electrochemical tests reveal that the Ir‐SrMnO3 exhibits a superior OER's activity with a low overpotential of 207 mV at 10 mA cm−2 and achieves a mass specific activity of 1100 A gIr−1 at 1.5 V. The proton‐exchange‐membrane water electrolyzer with the Ir‐SrMnO3 catalyst exhibits a low electrolysis voltage of 1.63 V at 1.0 A cm−2 and a stable 2000‐h operation with a decay of only 15 μV h−1 at 0.5 A cm−2. [ABSTRACT FROM AUTHOR]

The synthesized RuO2/MnCo2O4.5 nano-heterostructure possesses dense interfaces and abundant defect structures, synergistically balancing oxygen evolution reaction (OER) activity and stability. RuO2/MnCo2O4.5 exhibits a low overpotential of 190 mV at 10 mA cm−2. The proton exchange membrane (PEM) electrolyzer assembled can operate at 200 mA cm−2 stably for 50 h. [ABSTRACT FROM AUTHOR]

The strategic formulation of a compatible electrolyte plays a pivotal role in extending the longevity of lithium‐metal batteries (LMBs). Here, we present findings on a partially fluorinated electrolyte distinguished by a subdued solvation affinity towards Li+ ions and a concentrated anion presence within the primary solvation layer. This distinctive solvation arrangement redirects the focal points of reactions from solvent molecules to anions, facilitating the predominant involvement of anions in the creation of a LiF‐enriched solid‐electrolyte interphase (SEI). Electrochemical assessments showcase effective Li+ transport kinetics, diminished overpotential polarization for Li nucleation (28 mV), and prolonged cycling durability in Li||Li cells employing the partially fluorinated electrolyte. When tested in Li||NCM811 cells, the designed electrolyte delivers a capacity retention of 89.30 % and exhibits a high average Coulombic efficiency of 99.80 % over 100 cycles with a charge‐potential cut‐off of 4.6 V vs. Li/Li+ under the current density of 0.4C. Furthermore, even at a current density of 1C, the cells maintain 81.90 % capacity retention and a high average Coulombic efficiency of 99.40 % after 180 cycles. This work underscores the significance of weak‐solvation interaction in partially fluorinated electrolytes and highlights the crucial role of solvent structure in enabling the long‐term stability and high‐energy density of LMBs. [ABSTRACT FROM AUTHOR]

The development of electrocatalysts is of vital importance to the OER. In this work, an optimized MOF electrode, Ir-NiFe-btz/NF, was synthesized by incorporating ultralow levels of Ir nanoparticles into an ionic bimetallic MOF. Under alkaline conditions, the prepared MOF electrode demonstrated outstanding OER activity and stability with a low overpotential of 182 mV to reach 10 mA cm−2 and no obvious increase of overpotential in a chronovoltammetry test over 100 hours at 100 mA cm−2. [ABSTRACT FROM AUTHOR]

Alkaline water electrolysis was performed using Ni(OH) 2 /NiOOH as an anode and MmNi 5 -based hydrogen storage alloy as a cathode removed from NiMH batteries at 303 K and 10 mA/cm2 for 2 h. The water decomposition voltage changed from 1.36 V to 1.48 V (thermoneutral voltage: 1.48 V). The hydrogen evolution reaction (HER) overpotentials of the practically used MmNi 5 -based alloy with low H 2 dissociation pressure 0.012 MPa were small (33–75 mV) at 10 mA/cm2. The HER overpotentials were similar to those of Pt-based electrocatalysts. The low dissociation pressure of the hydride was suggested to play a key role to decrease the HER overpotentials of the alloy. The alkaline water electrolysis voltage was 1.46–1.48V and stable at 50 mA/cm2 and 353K for 24h. Then, the MmNi 5 -based hydrogen storage alloy was found to be a new type of HER electrocatalyst for alkaline water electrolysis. [Display omitted] • Alkaline water electrolysis was performed using Ni(OH) 2 and MmNi 5 -based alloy. • HER overpotentials of the alloy with low dissociation pressure were 33–75 mV. • The overpotentials of the alloy were similar to those of Pt-based electrocatalysts. • The dissociation pressure of the alloy hydride increased with the overpotential. • The water electrolysis voltage was stable at 50 mA/cm2 and 353K for 24h. [ABSTRACT FROM AUTHOR]

NiFe-based oxyhydroxides are promising electrocatalysts for the oxygen evolution reaction (OER) in alkaline media, but further enhancing their OER performance remains a significant challenge. Herein, we in situ incorporated polyoxometalates into NiFe oxyhydroxides to form a homogeneous/heterogeneous hybrid material, which induces the electronic interaction between Ni, Fe and Mo sites, as revealed by a variety of characterization experiments and theoretical calculations. The resulting hybrid electrocatalyst delivers a low overpotential of 203 mV at 10 mA cm−2 and a TOF of 2.34 s−1 at 1.53 V in alkaline media. This work presents a critical step towards developing high-performance OER catalysts by constructing metal–POM hybrids. [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) is the rate‐limiting step in water electrolysis due to its sluggish kinetic, and it is challenging to develop an OER catalyst that could work efficiently in both acid and alkaline environment. Herein, NiIr nanowire assembles (NAs) with unique nanoflower morphology were prepared by a facile hydrothermal method. As a result, the NiIr NAs exhibited superior OER activity in both acid and alkaline media. Specifically, in 0.1 M HClO4, NiIr NAs presented a superior electrocatalytic performance with a low overpotential of merely 242 mV at 10 mA cm−2 and a Tafel slope of only 58.1 mV dec−1, surpassing that of commercial IrO2 and pure Ir NAs. And it achieved a significantly higher mass activity of 148.40 A/g at −1.5 V versus RHE. In 1.0 M KOH, NiIr NAs has an overpotential of 291 mV at 10 mA cm−2 and a Tafel slope of 42.1 mV dec−1. Such remarkable activity makes the NiIr NAs among the best of recently reported representative Ir‐based OER electrocatalysts. Density functional theory (DFT) calculations confirmed alloying effect promotes surface bonding of NiIr with oxygen‐containing reactants, resulting in excellent catalytic properties. [ABSTRACT FROM AUTHOR]

FeNiOOH is regarded as the most stable active species in the oxygen evolution reaction (OER), but the high oxidation energy of NiOOH poses a challenge to directly synthesize FeNiOOH as a real OER catalyst. Herein, an anion‐mediated kinetically controlled strategy is proposed, coupled with cation‐induced geometric topology modulation, to directly synthesis FeNiOOH with ultra‐thin, densely packed nanosheet architectures. Specifically, the Cl−‐mediated in situ generation of hypochlorous acid promotes the direct formation of NiFeOOH. Concurrently, high‐valence competitive Ru3+ mitigate electrostatic repulsion, fostering a compact and densely packed assembly of Ru/FeNiOOH nanosheet branches. Furthermore, the intrinsic electron‐capturing ability of FeOOH, in synergy with the stabilizing effect of doped Ru atoms, further promote the formation and stabilization high‐valence NiOOH. Consequently, the hierarchical Ru/FeNiOOH@NiPOx nanoarray catalyst displays exceptional OER performance, with an overpotential of 172 mV at 10 mA cm−2 and outstanding stability. This study provides a novel strategy to directly construct a real catalyst. [ABSTRACT FROM AUTHOR]

Li─O2 batteries (LOBs) have the largest theoretical capacity among current batteries, but the irreversible growth and decomposition of Li2O2 products in positive electrodes cause dramatic degradation of their capacities over charging–discharging cycles. Herein, a metal–organic framework is reported with bipyridinic N linkers attached to graphene (bpyN‐MOF/g) as a positive electrode material to overcome the challenge. The bpyN‐MOF/g promotes conformal Li2O2 growth during discharging, while allowing Li2O2 decomposition at a low overpotential (0.487 V vs Li+/Li at 200 mA gc−1) during charging process, outperforming the Pt/C‐based electrode (0.857 V). Moreover, 3D‐tomography and density functional theory calculations consistently support the Li2O2 growth and decomposition mechanism inside bpyN‐MOF/g. Furthermore, bpyN‐MOF/g//Li LOBs achieve an exceptional discharge capacity (17 275 mAh gc−1 at 100 mA gc−1) and steady cycling for 270 cycles at 1000 mAh gc−1 under 2000 mA gc−1. Additionally, high gravimetric capacity at low mass loadings (0.27–0.44 mg cm−2) and stable cycle operation at a high areal current density (0.5 mA cm−2) open new opportunities for various practical applications. [ABSTRACT FROM AUTHOR]

The energy crisis stems from increasing demand, diminishing fossil fuel reserves, and insufficient investment in renewable alternatives, posing a profound threat to global energy security and environmental sustainability. Fuel cells offer promise as a solution to the energy crisis and the integration of two-dimensional carbon materials in fuel cell catalysts holds potential for enhancing efficiency, reducing costs, and improving the overall sustainability of fuel cell technologies. The new two-dimensional carbon form tetra-penta-octagonal-graphene and its boron doped derivative have been examined in this report for its applicability in the electrocatalytic oxygen reduction reaction for generation of electricity. The most favorable site for the reaction in the pristine specimen and the most favorable boron doping site have been carefully determined based on adsorption energy and formation energy, respectively. Projected density of states confirms a low density of states for the active site in both specimens. Boron doping causes a significant charge transfer from the primed site. The analysis of the four electron pathways along with the dioxygen adsorption step in the acidic medium has been conducted to gain a deeper understanding of the process. In both systems, the formation of the *O intermediate is associated with the highest Gibbs free energy change. The performance of the pristine material in the process has been found to support monotonically exothermic reaction with an overpotential of 0.622 V whereas the boron doped specimen presents very small barrier for the dioxygen adsorption step followed by monotonically exothermic reaction steps with overpotential 0.549 V. • A new sp2 stable 2D carbon allotrope TPO-graphene shows electrocatalytic activity. • Active site has lowest partial density of states at Fermi level. • Steps of ORR in four-electron pathway in acidic medium are monotonically exothermic. • TPO-graphene has a overpotential of 0.622 V for the ORR process. • Boron doping creates ORR catalysis site with lowest partial density of states. • Boron doped TPO-graphene has a overpotential of 0.549 V for the ORR process. [ABSTRACT FROM AUTHOR]

The meticulous design of heterogeneous interfaces presents a promising approach for enhancing the electrocatalytic activity of Cu-based materials in nitrate reduction reactions. Herein, we developed a self-templated metal–organic frameworks transformation strategy to synthesize hollow multi-metallic oxide materials with well-defined interfaces. By utilizing novel hollow Cu–Co bimetallic Prussian blue analogs as precursors, a hollow cage composed of ultra-small CuO/Co3O4 hetero-nanograins was successfully constructed. It was discovered that this structure greatly enhanced the electrocatalytic activity for the conversion of NO3− to NH3, achieving a remarkably high Faradaic efficiency (FE) for NH3 (with a maximum FE of 90.68%) at low overpotential ranges. Furthermore, electrochemical experiments and in situ spectroscopy provided evidence that electrochemically induced reconstruction led to the formation of synergistic sites between Cu and Co3O4. This enabled the sequential reduction of nitrate and nitrite on adjacent metal/metal oxide phases, resulting in the rapid generation of NH3. [ABSTRACT FROM AUTHOR]

Low ionic migration and compromised interfacial stability pose challenges for low‐temperature batteries. In this work, we discovered that even with the state‐of‐the‐art localized high‐concentration electrolytes (LHCEs), uncontrolled Na electrodeposition occurs with a huge overpotential of >1.2 V at −20 °C, leading to cell failure within tens of hours. To address this, we introduce a new electrolyte category that incorporates an ionic liquid as a key solvation species. Diverging from traditional LHCEs, the IL‐tailored LHCE facilitates an anion–solvent‐molecules exchange within the solvation sheath between Na+ and organic cations at low temperatures. This behavior reduces solvation cluster size and strengthens Na+–anion coordination, which proves instrumental in enabling fast ionic dynamics in both the bulk liquid and at the interface. Therefore, durable Na electrodeposition and shuttle‐free, 0.5 Ah sodium–sulfur pouch cells are achieved at −20 °C, for the first time, surpassing the limitations of typical LHCEs. This tailoring strategy opens a  new design direction for advanced batteries operating in fast‐charge and wide‐temperature scenarios. [ABSTRACT FROM AUTHOR]

As ammonia continues to gain more and more interest as a promising hydrogen carrier compound, so does the electrochemical ammonia oxidation reaction (AmOR). To avoid the liberation of H2 in a reverse Haber–Bosch reaction under release of the energetically more favorable N2, we propose the oxidation of ammonia to value‐added nitrite (NO2−), which is usually obtained during the Ostwald process. We investigated the anodic oxidation of gaseous ammonia directly supplied to a gas diffusion electrode (GDE) using a variety of compositionally different multi‐metal catalysts coated on Ni foam under the simultaneous formation of H2 at the cathode. This will double the amount of H2 per ammonia molecule while applying a lower overpotential than that required for water electrolysis (1.4–1.8 V vs. RHE at 50 mA ⋅ cm−2). A selectivity study demonstrated that some of the catalyst compositions were able to produce significant amounts of NO2−, and further investigations using the most promising catalyst composition Nif_AlCoCrCuFe integrated within a GDE demonstrated up to 88 % Faradaic efficiency for NO2− at the anode coupled to close to 100 % Faradaic efficiency for the cathodic H2 production. [ABSTRACT FROM AUTHOR]

A highly efficient electrocatalytic platform based on in situ formed metallic bismuth submicron crystals (microBi) was developed for 4-aminophenol electrosynthesis via the electrochemical reduction of 4-nitrophenol at acidic pH. The facile formation and high reactivity of microBi enable efficient electrosynthesis of 4-aminophenol with high selectivity (∼100%) at the expense of an ultra-low overpotential. [ABSTRACT FROM AUTHOR]

Facile preparation of low-cost electrocatalysts for an efficient oxygen evolution reaction (OER) is significant but remains a big challenge. Herein, a novel and facile strategy for transforming intrinsic non-stoichiometric ultrathin Co5(O9.48H8.52)NO3 nanosheets into oxygen-vacancy enriched Co3O4/CoOOH heterostructure nanosheets for an efficient OER was developed. The as-synthesized Co3O4/CoOOH heterostructure nanosheets displayed excellent OER performances, showing an extremely low overpotential of 260 mV at a current density of 10 mA cm−2, a relatively small Tafel slope of 52 mV dec−1, and a long-term durability of at least 20 h. This work provides a new way for the production of oxygen vacancies on metal (oxy)hydroxide nanosheets through electric-field assisted in situ transformation of non-stoichiometric metal oxyhydroxide nanosheets. [ABSTRACT FROM AUTHOR]

An advance of highly efficient nanostructured electrocatalysts based on non-noble metals for water electrolysis and urea oxidation reaction (UOR) are of great significance for urea-enriched wastewater remediation and producing hydrogen. Herein, we report V x Ni 1-x O catalysts supported on three-dimensional Ni-foam scaffold for catalytic water and urea electrolysis. V x Ni 1-x O catalysts show rapid water and urea electrolysis due to enhanced electrochemical surface area (ECSA). Most important of all, the urea oxidation reaction has a lower potential of 1.418V vs RHE as compared to oxygen evolution reaction (1.684 V vs RHE) system to generate 100 mA/cm2. Additionally, a two-electrode cell for bi-functional water electrolysis generates 100 mA/cm2 at a potential of 2.10 V at 20 °C and just 1.86 V at 60 °C temperature due to regulated the adsorption/desorption of intermediates species, enhanced charge and mass transport, and easier desorption of oxygen molecules from the anode. The stability of V x Ni 1-x O catalyst was measured at 1000 mA/cm2 current density for up to 17 h. • Doping energy strategy to design a vertical V x Ni 1-x O nanosheets for water and urea electrolysis. • Overpotential of 454 mV for OER and 271 mV for HER at 100 mA/cm2. • Maximum current of 1000 mA/cm2 is achieved at a cell potential of 2.3 V. • V 0.1 Ni 0.9 O catalyst shows he stability for 17 h at 1000 mA/cm2. • Urea electrolysis system has a lower cell potential of 1.418V at 100 mA/cm2. [ABSTRACT FROM AUTHOR]

Secondary non-aqueous magnesium-based batteries are a promising candidate for post-lithium-ion battery technologies. However, the uneven Mg plating behavior at the negative electrode leads to high overpotential and short cycle life. Here, to circumvent these issues, we report the preparation of a magnesium/black phosphorus (Mg@BP) composite and its use as a negative electrode for non-aqueous magnesium-based batteries. Via in situ and ex situ physicochemical measurements, we demonstrate that Mg ions are initially intercalated in black phosphorus two-dimensional structures, forming chemically stable MgxP intermediates. After the formation of the intermediates, Mg electrodeposition reaction became the predominant. When tested in the asymmetric coin cell configuration, the Mg@BP composite electrode allowed stable stripping/plating performances for 1600 h (800 cycles), a cumulative capacity of 3200 mAh cm−2, and a Coulombic efficiency of 99.98%. Assembly and testing of the Mg@BP | |nano-CuS coin cell enabled a discharge capacity of 398 mAh g−1 and an average cell discharge potential of about 1.15 V at a specific current of 560 mA g−1 with a low decay rate of 0.016% per cycle for 225 cycles at 25 °C. Uneven Mg plating behaviour at the negative electrode leads to high plating overpotential and short cycle life. Here, to circumvent these issues, authors report the preparation of a magnesium/black phosphorus composite and its use as a negative electrode for non-aqueous magnesium-based batteries. [ABSTRACT FROM AUTHOR]

Despite considerable progress, high-performing durable catalysts operating under large current densities (i.e., >1000 mA/cm2) are still lacking. To discover platinum group metal-free (PGM-free) electrocatalysts for sustainable energy, our research involves investigating layered topological magnetic materials (semiconducting ferromagnets) as highly efficient electrocatalysts for the hydrogen evolution reaction under high current densities and establishes the novel relations between structure and electrochemical property mechanisms. The materials of interest include transition metal trihalides, i.e., CrCl3, VCl3, and VI3, wherein a structural unit, the layered structure, is formed by Cr (or V) atoms sandwiched between two halides (Cl or I), forming a tri-layer. A few layers of quantum crystals were exfoliated (~50−60 nm), encapsulated with graphene, and electrocatalytic HER tests were conducted in acid (0.5M H2SO4) and alkaline (1M KOH) electrolytes. We find a reasonable HER activity evolved requiring overpotentials in a range of 30–50 mV under 10 mA cm−2 and 400−510 mV (0.5M H2SO4) and 280−500 mV (1M KOH) under −1000 mA cm−2. Likewise, the Tafel slopes range from 27 to 36 mV dec−1 (Volmer–Tafel) and 110 to 190 mV dec−1 (Volmer–Herovsky), implying that these mechanisms work at low and high current densities, respectively. Weak interlayer coupling, spontaneous surface oxidation, the presence of a semi-oxide subsurface (e.g., O–CrCl3), intrinsic Cl (or I) vacancy defects giving rise to in-gap states, electron redistribution (orbital hybridization) affecting the covalency, and sufficiently conductive support interaction lowering the charge transfer resistance endow the optimized adsorption/desorption strength of H* on active sites and favorable electrocatalytic properties. Such behavior is expedited for bi-/tri-layers while exemplifying the critical role of quantum nature electrocatalysts with defect sites for industrial-relevant conditions. [ABSTRACT FROM AUTHOR]

Ensuring effective and controlled zinc ion transportation is crucial for functionality of the solid electrolyte interphase (SEI) and overall performance in zinc‐based battery systems. Herein the first‐ever demonstration of incorporate cation‐π interactions are provided in the SEI to effectively facilitate uniform zinc ion flux. The artificial SEI design involves the immobilization of 4‐amino‐p‐terphenyl (TPA), a strong amphiphilic cation‐π interaction donor, as a monolayer onto a conductive poly(3,4‐ethylenedioxythiophene) (PEDOT) matrix, which enable the establishment of a robust network of cation‐π interactions. Through a carefully‐designed interfacial polymerization process, a high‐quality, large‐area, robust is achieved, thin polymeric TPA/PEDOT (TP) film for the use of artificial SEI. Consequently, this interphase exhibits exceptional cycling stability with low overpotential and enables high reversibility of Zn plating/stripping. Symmetrical cells with TP/Zn electrodes can be cycled for more than 3200 hours at 1 mA cm−2 and 1 mAh cm−2. And the asymmetric cells can cycle 3000 cycles stably with a high Coulomb efficiency of 99.78%. Also, under the extreme conditions of lean electrolyte and low N/P ratio, the battery with TP protective layer can still achieve ultra‐stable cycle. [ABSTRACT FROM AUTHOR]

A systematic investigation of the electrochemical iron nitride synthesis in a LiCl/KCl salt melt at 723 K shows an optimum of ϵ -Fe 3 N 1 + x formation in the range of 2.2 to 2.3 V and for γ ′ -Fe 4 N between 2.4 and 2.5 V enabling the control of the desired iron nitride phase by setting the supplied terminal voltage. The product formation of iron nitrides starts when the electrochemical window is reached, which could be verified by linear sweep voltammetry. Hence, a maximum of nitrogen content in the formed iron nitride phases is observed for 2.27 V. During elongated synthesis periods, convection emerges as the predominant transport mechanism hindering an accelerated reaction rate with higher overpotential applied. Real-time analysis of the background current allows conclusions about the remaining nitride concentration. Additionally, there is concurrent iron nitride formation at the electrode surface through nitride adsorption and autonucleation-induced precipitation of iron and nitride ions. The analysis of the amount of sediment in comparison to the layer thickness of the nitrided working electrode suggests that the autonucleation mechanism dominates over the adsorption mechanism with increasing overpotential and can be further enhanced by this feature. [ABSTRACT FROM AUTHOR]