Enhanced Alkaline Hydrogen Evolution Reaction Research Articles

Synthesis Framework for Designing PtPdCoNiMn High-Entropy Alloy: A Stable Electrocatalyst for Enhanced Alkaline Hydrogen Evolution Reaction.

High entropy alloys (HEAs) are an emerging class of advanced materials characterized by their multifunctionality and potential to replace commercial catalysts in electrocatalytic water splitting. The synergy among the various alloyed elements in HEAs makes them particularly promising for applications in electrocatalysis. However, preparation of HEA via bottom-up approaches by avoiding the formation of mono, di, and tri metallic alloys in the nanoscale is challenging. This aspect is addressed, in this study by exploring the logical selection of solvents, reducing agents, and capping agents, along with their relative fractions, in the solvothermal synthesis of the HEA comprising platinum-palladium-cobalt-nickel-manganese (PtPdCoNiMn). It is established that the reducing capabilities of both the solvent and reducing agent are crucial for the reduction of each metal to form a single-phase HEA. The synthesized HEA (20 wt.%)/functionalized carbon (FC) demonstrates excellent performance as an HER catalyst, exhibiting a low overpotential of 48.7mV at -10 mA cm-2 in an alkaline electrolyte. This performance is characterized by high reaction kinetics and stability at elevated current densities. Furthermore, the catalyst shows impressive performance in both simulated and actual seawater. This development reduces the reliance on platinum while enhancing the long-term durability and catalytic efficiency of the electrocatalyst.

Growth of octahedral structured AgBiS2 single crystals and its insights on the high performance electrocatalytic hydrogen generation

Given the enormous depletion of fossil fuels and growing environmental concerns, there is an immediate need to develop alternative and clean energy sources. Hydrogen (H2), recognized for its cleanliness and renewability, is poised to meet future energy requirements. Consequently, ongoing research is focused on the development of electro-active, durable, and cost-effective catalysts to replace expensive noble metal-based electrocatalysts. In this study, microscale AgBiS2 chalcogenide derived from a single crystal is reported as promising electrocatalysts for the Hydrogen Evolution Reaction (HER) with a remarkably low overpotential. The physico-chemical characterization of the AgBiS2 catalyst has been investigated using various analytical techniques. The synthesized AgBiS2 catalyst exhibits excellent HER activity, manifesting a low overpotential of 86 mV at a current density of 10 mA cm−2 and a Tafel slope of 44 mV dec−1, along with superior stability even after 24 h in HER at a very high current density. The developed AgBiS2 also showcased stable production when subjected to a two-electrode system. The enhanced alkaline HER activity of AgBiS2 can be attributed to its phase purity, high crystallinity, and the presence of high active sites. The observed high electrochemical performance and stability position AgBiS2 as a potential electrocatalyst for the hydrogen evolution reaction. This finding holds significant promise in the quest for efficient, durable, and economically viable catalysts to drive the shift towards clean and renewable energy sources.

Facet‐Junction Induced Strong Metal Support Interaction for Enhanced Alkaline Hydrogen Evolution Reaction

AbstractStrong metal‐support interaction (SMSI) plays a critical role in enhancing the catalytic performance of electrocatalysts. Currently, effective approaches to enhance the SMSI effect in supported electrocatalysts still need to be developed, and a comprehensive atomic‐level understanding of the underlying reaction mechanisms remains unclear. In this study, a novel facet‐junction strategy is proposed to enhance the SMSI between the loaded Ru atoms and the Co3O4 support. By modulating the ratio of exposed facet for (111)/(100) crystal plane in Co3O4, the hydrogen evolution reaction (HER) performance can be dramatically enhanced by 560% and can achieve a Pt‐like HER activity with the overpotential of 45 mV. Detailed analysis with atomic‐resolution integrated differential phase contrast (iDPC)‐scanning transmission electron microscopy (STEM), atomic‐resolution high angle annular dark field (HADDF)‐STEM, and electron energy loss spectroscopy (EELS) further proved that with proper (111)/(100) crystal plane ratio, the intensified charge distribution near the facet‐junction region would modify the electronic structure around the active sites. This work provides new insights to enhance the SMSI and will contribute to the rational design of highly efficient electrocatalysts for water splitting.

Enhanced Alkaline Hydrogen Evolution Reaction via Electronic Structure Regulation: Activating PtRh with Rare Earth Tm Alloying.

Developing high-performance electrocatalysts for alkaline hydrogen evolution reaction (HER) is crucial for producing green hydrogen, yet it remains challenging due to the sluggish kinetics in alkaline environments. Pt is located near the peak of HER volcano plot, owing to its exceptional performance in hydrogen adsorption and desorption, and Rh plays an important role in H2O dissociation. Lanthanides (Ln) are commonly used to modulate the electronic structure of materials and further influence the adsorption/desorption of reactants, intermediates, and products, and noble metal-Ln alloys are recognized as effective platforms where Ln elements regulate the catalytic properties of noble metals. Here Pt1.5Rh1.5Tm alloy is synthesized using the sodium vapor reduction method. This alloy demonstrates superior catalytic activity, being 4.4 and 6.6 times more effective than Pt/C and Rh/C, respectively. Density Functional Theory (DFT) calculations reveal that the upshift of d-band center and the charge transfer induced by alloying promote adsorption and dissociation of H2O, making Pt1.5Rh1.5Tm alloy more favorable for the alkaline HER reaction, both kinetically and thermodynamically.

Enhanced alkaline hydrogen evolution reaction of MoO2/Ni3S2 nanorod arrays by interface engineering

Interface engineering is verified as an efficient strategy for enhancing the intrinsic activity of transition metal-based electrocatalysts in alkaline hydrogen evolution reaction (HER). Here, the heterostructural MoO2/Ni3S2 nanorod arrays fabricated on nickel foam (MoO2/Ni3S2/NF) are produced by a straightforward and effective hydrothermal approach. Benefiting from interfacial effect and self-supported structure, MoO2/Ni3S2/NF electrocatalyst exhibits remarkable HER catalytic properties and durability with a low overpotential of 74.0 mV for achieving a current density of 10 mA cm−2 in 1.0 M KOH, as well as a long-term stability without obvious attenuation. Density functional theory (DFT) calculations reveal electron transfer at the interface domain reduces the energy barrier of the water dissociation step and optimizes H adsorption capability, thereby expediting HER kinetics in alkaline media. This work provides a viable strategy based on interfacial engineering for designing high-efficient HER electrocatalysts.

Interface Engineering with the Coupling of a 3D Porous Structure Enables MoP2-NiCoP Heterostructure Nanosheets for Enhanced Alkaline Hydrogen Evolution Reaction.

One of the crucial parts of the electrochemically focused energy conversion and storage system is the hydrogen evolution reaction. The further exploration of electrocatalysts made of nonprecious metals could help to bring the technology closer to industrialization. Here, we present an effective hydrogen evolution reaction (HER) electrocatalyst that employs hydrothermal and phosphorization steps to create three-dimensional (3D) porous MoP2-NiCoP heterostructure nanosheets on nickel foam (MoP2-NiCoP/NF). H2O-dissociation and H-adsorption were effectively achieved due to the distinctive interface engineering between NiCoP and MoP2, which functions as a channel for immediate electron transfer. Compared to the single-component MoP2 and NiCoP, the synergistic interaction between the heterogeneous components coupling and the 3D porous structure enables MoP2-NiCoP/NF to exhibit satisfactory catalytic activity with an ultralow overpotential of 50 mV at 10 mA cm-2, which is close to the commercial Pt/C catalyst in alkaline media. More importantly, it exhibits good stability, with the ability to be electrolyzed in 1.0 M KOH electrolyte for 24 h without a significant change in overpotential. This study offers directions for the design of low-cost, high-activity, transition metal phosphides (TMPs)-based HER catalyst alternatives for future practical applications.

Synergistic interfacial electronic modulation of topotactically developed bimetallic CoNiP on NiS nanorods for enhanced alkaline hydrogen evolution reaction.

Designing hybrid transition metal phosphosulfide electrocatalysts is critical for the hydrogen evolution reaction (HER). We propose a novel approach by designing a hierarchical structure of cobalt phosphide (CoP) and nickel phosphide (Ni8P3) nanoparticles topotactically developed on nickel sulfide (Ni3S2) nanorods (CoNiP/NiS) via a sulfuration-phosphorization strategy using conductive 3D nickel foam. Hierarchical heterostructured nanorods were achieved without the need for template removal steps or the assistance of surfactants. This not only simplifies the process but also improves the exposure of active sites for catalytic purposes. Furthermore, the theoretical calculation results revealed that the high H* adsorption-free energy for CoP and Ni8P3 phases significantly decreases upon coupling with Ni3S2, which indicates that the interfacial electronic interaction synergistically modulates both CoP and Ni8P3 (CoNiP) at the coupled interfaces and facilitates the adsorption and desorption of H* intermediates during the HER process. The resulting electrode exhibits excellent performance in the HER catalytic process and shows great performance for further exploration in the urea oxidation reaction (UOR). Our work provides a stepping stone toward rational topotactic transformation of active materials on porous substrates, using electronic structure regulation and heterointerfaces to produce promising electrocatalysts for sustainable, large-scale hydrogen production from water electrolysis.

Tailoring the electronic environment of MoSe2via cation metal doping for the enhanced alkaline hydrogen evolution reaction

A series of cation metal doped MoSe2-based catalysts with an enriched edge active sites using a straightforward one-pot hydrothermal treatment is designed.

(Invited) Development of Sustainable Electrocatalysts for Anion Exchange Membrane Fuel Cells and Electrolyzers

The electrocatalytic hydrogen oxidation (HOR) and evolution (HER) reactions under alkaline conditions are kinetically slow processes even when Pt group metals are employed. This presentation discusses our strategies to improve the activity of non platinum catalysts. For example, to improve the alkaline HOR activity of transition metal nanoparticles we look at engineering strong interactions with metal oxides incorporated with carbon-based catalyst supports.(1,2) Another strategy involves utilizing novel carbon materials such as onion like carbon (OLC). We have shown that the combination of CeO2 and OLC in Pd–CeO2/OLC induces surface defects and modifies the electronic structure of the Pd-OLC interface, significantly improving electrical conductivity due to enhanced charge redistribution. Such results were corroborated by density functional theory (DFT) calculations.(3) Using this strategy, peak power densities of up to 2 W cm-2 have been achieved when Pd-CeO2 is incorporated in AEMFCs.(4) Regarding the alkaline HER, mixed phase Ni-Mo and MoO3-x materials are known to have enhanced alkaline hydrogen evolution reaction (HER) activity. Here we describe the optimization of the preparation of an active HER catalyst composed of MoO2 surface nanorod arrays on nickel foam (see Figure). Large circular cathode electrodes (Area 80 cm2) were prepared and tested in a three cell stack AEM electrolyser.(5) M. V. Pagliaro, C. L. Wen, B. Sa, B. Y. Liu, M. Bellini, F. Bartoli, S. Sahoo, R. K. Singh, S. P. Alpay, H. A. Miller and D. R. Dekel, ACS Catal., 10894 (2022).M. V. Pagliaro, M. Bellini, F. Bartoli, J. Filippi, A. Marchionni, C. Castello, W. Oberhauser, L. Poggini, B. Cortigiani, L. Capozzoli, A. Lavacchi, H. A. Miller and F. Vizza, Inorg. Chim. Acta, 543 (2022).J. Ogada, A. K. Ipadeola, P. V. Mwonga, A. B. Haruna, F. Nichols, S. W. Chen, H. A. Miller, M. V. Pagliaro, F. Vizza, J. R. Varcoe, D. M. Meira, D. M. Wamwangi and K. I. Ozoemena, ACS Catal., 12, 10938 (2022).H. A. Miller, M. Bellini, D. R. Dekel, and F. Vizza, Electrochemistry Communications, 135, 107219 (2022).F. Bartoli, L. Capozzoli, T. Peruzzolo, M. Marelli, C. Evangelisti, k. Bouzek, J. Hnat, G. Serrano, L. Poggini, K. Stojanovski, V. Briega-Martos, S. Cherevko, H. A. Miller and F. Vizza, J. Mater. Chem. A, 11, 5789 (2023). Figure 1

Constructing Interfacial Oxygen Vacancy and Ruthenium Lewis Acid–Base Pairs to Boost the Alkaline Hydrogen Evolution Reaction Kinetics

AbstractSimultaneous optimization of the energy level of water dissociation, hydrogen and hydroxide desorption is the key to achieving fast kinetics for the alkaline hydrogen evolution reaction (HER). Herein, the well‐dispersed Ru clusters on the surface of amorphous/crystalline CeO2‐δ (Ru/ac‐CeO2‐δ) is demonstrated to be an excellent electrocatalyst for significantly boosting the alkaline HER kinetics owing to the presence of unique oxygen vacancy (VO) and Ru Lewis acid–base pairs (LABPs). The representative Ru/ac‐CeO2‐δ exhibits an outstanding mass activity of 7180 mA mgRu−1 that is approximately 9 times higher than that of commercial Pt/C at the potential of −0.1 V (V vs RHE) and an extremely low overpotential of 21.2 mV at a geometric current density of 10 mA cm−2. Experimental and theoretical studies reveal that the VO as Lewis acid sites facilitate the adsorption of H2O and cleavage of H‐OH bonds, meanwhile, the weak Lewis basic Ru clusters favor for the hydrogen desorption. Importantly, the desorption of OH from VO sites is accelerated via a water‐assisted proton exchange pathway, and thus boost the kinetics of alkaline HER. This study sheds new light on the design of high‐efficiency electrocatalysts with LABPs for the enhanced alkaline HER.

Constructing Interfacial Oxygen Vacancy and Ruthenium Lewis Acid-Base Pairs to Boost the Alkaline Hydrogen Evolution Reaction Kinetics.

Simultaneous optimization of the energy level of water dissociation, hydrogen and hydroxide desorption is the key to achieving fast kinetics for the alkaline hydrogen evolution reaction (HER). Herein, the well-dispersed Ru clusters on the surface of amorphous/crystalline CeO2-δ (Ru/ac-CeO2-δ ) is demonstrated to be an excellent electrocatalyst for significantly boosting the alkaline HER kinetics owing to the presence of unique oxygen vacancy (VO ) and Ru Lewis acid-base pairs (LABPs). The representative Ru/ac-CeO2-δ exhibits an outstanding mass activity of 7180 mA mgRu -1 that is approximately 9 times higher than that of commercial Pt/C at the potential of -0.1 V (V vs RHE) and an extremely low overpotential of 21.2 mV at a geometric current density of 10 mA cm-2 . Experimental and theoretical studies reveal that the VO as Lewis acid sites facilitate the adsorption of H2 O and cleavage of H-OH bonds, meanwhile, the weak Lewis basic Ru clusters favor for the hydrogen desorption. Importantly, the desorption of OH from VO sites is accelerated via a water-assisted proton exchange pathway, and thus boost the kinetics of alkaline HER. This study sheds new light on the design of high-efficiency electrocatalysts with LABPs for the enhanced alkaline HER.

Enhanced Alkaline Hydrogen Evolution Reaction through Lanthanide-Modified Rhodium Intermetallic Catalysts.

Design of highly efficient electrocatalysts for alkaline hydrogen evolution reaction (HER) is of paramount importance for water electrolysis, but still a considerable challenge because of the slow HER kinetics in alkaline environments. Alloying is recognized as an effective strategy to enhance the catalytic properties. Lanthanides (Ln) are recognized as an electronic and structural regulator, attributed to their unique 4f electron behavior and the phenomenon known as lanthanide contraction. Here, a new class of Rh3Ln intermetallics (IMs) are synthesized using the sodium vapor reduction method. The alloying process induced an upshift of the d-band center and electron transfer from Ln to Rh, resulting in optimized adsorption and dissociation energies for H2O molecules. Consequently, Rh3Tb IMs exhibited outstanding HER activity in both alkaline environments and seawater, displaying an overpotential of only 19mV at 10mAcm-2 and a Tafel slope of 22.2mV dec-1. Remarkably, the current density of Rh3Tb IMs at 100mV overpotential is 8.6 and 5.7 times higher than that of Rh/C and commercial Pt/C, respectively. This work introduces a novel approach to the rational design of HER electrocatalysis and sheds light on the role of lanthanides in electrocatalyst systems.

Interface engineering of Ni2P/MoOx decorated NiFeP nanosheets for enhanced alkaline hydrogen evolution reaction at high current densities

The rational design of high-performance non-noble metal electrocatalysts at large current densities is important for the development of sustainable energy conversion devices such as alkaline water electrolyzers. However, improving the intrinsic activity of those non-noble metal electrocatalysts remains a great challenge. Therefore, Ni2P/MoOx decorated three-dimensional (3D) NiFeP nanosheets (NiFeP@Ni2P/MoOx) with abundant interfaces were synthesized using facile hydrothermal and phosphorization methods. NiFeP@Ni2P/MoOx exhibits excellent electrocatalytic activity for hydrogen evolution reaction (HER) at a high current density of −1000 mA cm−2 with a low overpotential of 390 mV. Surprisingly, it can operate steadily at a large current density of −500 mA cm−2 for 300 h, indicating its long-term durability under high current densities. The boosted electrocatalytic activity and stability can be ascribed to the as-fabricated heterostructures via interface engineering, leading to modifying the electronic structure, improving the active area, and enhancing the stability. Besides, the 3D nanostructure is also beneficial for exposing abundant accessible active sites. Therefore, this research proposes a considerable route for fabricating non-noble metal electrocatalysts by interface engineering and 3D nanostructure applied in large-scale hydrogen production facilities.

Magnetic field induced synthesis of (Ni, Zn)Fe2O4 spinel nanorod for enhanced alkaline hydrogen evolution reaction

Recently, the introduction of external fields (light, thermal, magnetism, etc.) during electrocatalysis reactions gradually becomes a new strategy to modulate the catalytic activities. In this work, an external magnetic field was innovatively employed for the synthesis progress of (Ni, Zn)Fe2O4 spinel oxide (M-(Ni, Zn)Fe2O4). Results indicated the magnetic field (≤250 ​mT) would affect the morphology of catalyst due to the existing Fe ions, inducing the M-(Ni, Zn)Fe2O4 nanosphere particles to be uniform and coral-like nanorods. In addition, the electronic structure of the catalyst was regulated by the valence state of Fe, changing the bonding of metal to oxygen atoms in different spinel sites. The results manifested that the M-(Ni, Zn)Fe2O4 requires a lower overpotential of only 67 ​mV to deliver 10 ​mA ​cm−2 for hydrogen evolution reaction (HER) in alkaline electrolyte. Moreover, M-(Ni, Zn)Fe2O4 respectively as the anode and cathode electrode for the overall water splitting, the catalysis system requires a cell voltage of only 1.76 ​V to gain a current density of 50 ​mA ​cm−2, combining with an excellent discharging stability after 10 ​h. This work provides a facile synthesis strategy toward the design of efficient non-noble metal catalysts for alkaline HER and overall water splitting.

Universal phase transformation of Ni–Se electrocatalysts induced by an electrochemical activation strategy for a significantly enhanced alkaline hydrogen evolution reaction

A general electrochemical activation strategy is reported to induce the phase transformation from Ni0.85Se to NiSe/Ni3Se2 with a core–shell structure.

Facile and rapid synthesis of ultrafine RuPd alloy anchored in N-doped porous carbon for superior HER electrocatalysis in both alkaline and acidic media

Searching for preeminent electrocatalysts toward hydrogen evolution reaction (HER) is significantly important in transforming renewable electricity to clean hydrogen energy by electrochemical water splitting. Herein, ultrafine RuPd alloy nanoparticles anchored in MOFs-derived N-doped porous carbon dodecahedrons (Ru x Pd 1−x @NPC) were synthesized by microwave-assisted ethylene glycol reduction method. Due to the synergistic promotion by modulating the composition and structure, excellent HER catalytic performance was achieved in both alkaline and acidic media for the as-prepared Ru x Pd 1−x @NPC electrocatalysts with low noble metal loading. In which, Ru 0.7 Pd 0.3 @NPC exhibited significantly enhanced alkaline HER activity with a low overpotential of only 20 mV to reach a current density of 10 mA cm −2 . Meanwhile, Ru 0.3 Pd 0.7 @NPC showed admirable HER activity in acidic media, which delivered an overpotential of 36 mV at 10 mA cm −2 . Additionally, the proposed catalysts demonstrated high mass activity and good long-term stability in both alkaline and acidic condition, remarkably surpassing the commercial Pt/C catalyst. The superior activity of the Ru x Pd 1−x @NPC catalysts is attributed to improved intrinsic activity, fast charge transfer kinetics and distinct electrochemical active surface areas after alloying. This work provides a rapid and facile synthesis of highly efficient, durable and affordable alloy electrocatalysts for hydrogen evolution. With low noble metal loading, the alloying Ru x Pd 1−x @NPC electrocatalysts synthesized by facile and rapid microwave-assisted reduction method exhibit dramatically enhanced performance for sustainable hydrogen evolution. • Series of ultrafine alloying RuPd nanoparticles are dispersedly encapsulated in N-doped porous carbon dodecahedrons. • A facile and rapid microwave-assisted reduction method is proposed to synthesize RuPd alloy catalysts. • Enhanced HER electrocatalytic performance is realized in both alkaline and acidic media .

Refining the surface properties of WO2.7 by vacancy engineering and transition metals doping for enhanced alkaline hydrogen evolution reaction

Anion-exchange membrane water electrolyzer is a promising and green technology for hydrogen production. However, the high energy barriers for the water dissociation step for breaking the strong HOH covalent bond results in sluggish hydrogen evolution reaction (HER) kinetics at the cathode. Herein, we present a strategy to optimize the morphology and surface properties of WO2.7 by introducing oxygen vacancies and doping with various transition metals. The experimental analysis demonstrates that the developed Co-WO2.7-x and Ni-WO2.7-x with ultrafine nanorods structure provide a larger electrochemical surface area than the other synthesized catalysts. Furthermore, theoretical analysis reveals that Co-WO2.7-x has the lowest energy barrier (0.65 eV) for the water dissociation step, which is much lower than that of WO2.7 (2.61 eV). Consequently, the Co-WO2.7-x delivers a current of 10 mA cm−2 at a small overpotential of 59 mV for alkaline HER.

Cathode electrochemically reconstructed V-doped CoO nanosheets for enhanced alkaline hydrogen evolution reaction

• The crystalline V-doped CoO nanosheets were obtained by cathode electrochemical reconstruction of amorphous VCoO. • The crystallineV-doped CoO exhibited better HER active than amorphous VCoO. • Nanosheets structure could provide abundant active sites. • Vanadium doping effectively increased the intrinsic activity of CoO (1 1 1) and the number of active sites. • The V-doped CoO nanosheets display superb performance for HER at high potential. In the search for nonprecious metal catalysts to achieving active industrial hydrogen evolution reaction (HER), transition metal oxides (TMOs) have been proposed as promising candidates. In various synthetic methods for preparation of TMO electrocatalysts, electrochemical reconstruction, as one of the most efficient and controlled way, attracts much attentions. However, most of reported electrochemical reconstruction is usually carried out on the surface of anode via electrochemical oxidation reaction, and the investigations of cathode electrochemical reconstruction are rarely reported. Here, V-doped CoO nanosheets (V-CoO) are successfully prepared via cathode electrochemical reconstruction of amorphous VCoO. The reconstruction process and principle are studied in detail. Compared with the previous oxides, the obtained V-CoO possesses the promoted HER performance with overpotential of 280 mV at − 100 mA cm −2 and superior durability at − 1.07 V vs. RHE for 20 h. DFT calculations further reveals that vanadium doping effectively improves the intrinsic activity of oxides and HER active sites located at Co side of V-CoO (1 1 1) facet is the favorable H* adsorption site of reconstructed oxides. This work highlights the importance of electrochemical reconstruction on cathode to improve the HER activity of TMOs.

Nitrogen-Doped Cobalt Diselenide with Cubic Phase Maintained for Enhanced Alkaline Hydrogen Evolution.

The introduction of heteroatoms is one of the most important ways to modulate the intrinsic electronic structure of electrocatalysts to improve their catalytic activity. However, for transition metal chalcogenides with highly symmetric crystal structure (HS-TMC), the introduction of heteroatoms, especially those with large atomic radius, often induces large lattice distortion and vacancy defects, which may lead to structural phase transition of doped materials or structural phase reconstruction during the catalytic reaction. Such unpredictable situations will make it difficult to explore the connection between the intrinsic electronic structure of doped catalysts and catalytic activity. Herein, taking thermodynamically stable cubic CoSe2 phase as an example, we demonstrate that nitrogen incorporation can effectively regulate the intrinsic electronic structure of HS-TMC with structural phase stability and thus promote its electrocatalytic activity for the hydrogen evolution activity (HER). In contrast, the introduction of phosphorus can lead to structural phase transition from cubic CoSe2 to orthorhombic phase, and the structural phase of phosphorus-doped CoSe2 is unstable for HER.

Synergistically enhanced alkaline hydrogen evolution reaction by coupling CoFe layered double hydroxide with NiMoO4 prepared by two-step electrodeposition

The optimized CoFe LDH/NiMoO4/Cu NW/Cu foam as HER electrocatalyst presents promising application prospect in water splitting with ultralow overpotential of 45 mV at -10 mA/cm2 and long-term durability.