Electrocatalyst For Hydrogen Evolution Research Articles

Electronic Structure Modulating of W 18 O 49 Nanospheres by Niobium Doping for Efficient Hydrogen Evolution Reaction.

Developing efficient electrocatalysts to reduce HER overpotential is vital to enhance hydrogen production efficiency and minimize energy consumption. Adjusting the electronic structure of transition metal oxides via elemental doping is a potent strategy to improve the effectiveness of electrocatalysts for hydrogen evolution. In this work, we synthesized a set of niobium-doped tungsten oxides (Nbx-W18O49) under anoxic conditions using a straightforward "one-pot" solvothermal approach. After doping Nb, the oxygen vacancy content inside W18O49was increased, which induced a synergistic effect with the active sites of tungsten. In acidic environments, the hydrogen evolution activity of the Nb0.6-W18O49electrocatalyst is secondonly by 20 wt% Pt/C. It attains a current density of -10 mA cm-2at an overpotential of 102 mV. By comparison with W18O49, Nb0.4-W18O49and Nb0.5-W18O49, Nb0.6-W18O49demonstrates a reduced charge transfer resistance, which significantly enhances its conductivity and the speed of electron movement across interfaces. Coupled with this feature are notably faster HER kinetics. Additionally, it exhibits excellent stability, meaning it maintains its performance and structural integrity over prolonged periods and under various operational conditions. This article provides a new perspective for discovering inexpensive and efficient hydrogen evolution electrocatalyst materials.

Advanced multi-component FeCoCuAlMo intermetallic electrocatalysts for efficient and sustainable hydrogen evolution in alkaline freshwater and seawater

Electrolyzing seawater to produce hydrogen is a promising sustainable energy production technology. The current non-precious metal-based hydrogen evolution reaction (HER) electrocatalysts demonstrate inadequate catalytic activity and poor stability in seawater electrolyte. Therefore, developing stable and efficient non-precious metal-based HER electrocatalysts is a major challenge for achieving sustainable green energy development. This work reports a multi-component intermetallic catalyst FeCoCuAlMo prepared by arc melting and chemical dealloying methods. The electrocatalytic hydrogen evolution performance of catalysts with varying atomic ratios (FeCoCu)20(Al70Mo30)80, (FeCoCu)30(Al70Mo30)70, (FeCoCu)40(Al70Mo30)60, and (FeCoCu)50(Al70Mo30)50 in alkaline seawater and alkaline electrolyte was studied. The findings indicate that these catalysts primarily consist of AlMo3 and (Cu0.35Fe0.35Co0.3)Al, among which the dealloyed (FeCoCu)30(Al70Mo30)70 exhibits excellent catalytic activity with overpotentials of 137.54 and 116.91 mV at a current density of 100 mA/cm2 in alkaline seawater and alkaline electrolyte, respectively, outperforming most catalysts. Additionally, it demonstrated long-term stability in alkaline seawater and alkaline electrolyte for 250 and 400 h without significant decay at overpotentials of 236 mV and 276 mV, respectively. This improved performance can be attributed to the unique structure of the multi-component intermetallic compound, which provides good thermodynamic stability and synergistic effects among its constituents, thereby enhancing HER performance. Within this multi-component intermetallic compound, AlMo3 particles serve as the primary conductive medium to accelerate electron transfer, while (Cu0.35Fe0.35Co0.3)Al serves as the main active site, resulting in a stable structure that provides the catalyst with high catalytic activity and good stability. Thus, the (FeCoCu)30(Al70Mo30)70 electrocatalyst is a promising candidate for seawater electrolysis aimed at hydrogen production.

Electrodeposited zinc cobalt bimetallic phosphate as a bifunctional catalyst for hydrogen evolution and urea oxidation

The theoretical potential of the urea oxidation reaction (UOR) is a mere 0.37V(vs.RHE), significantly lower than the 1.23V (vs. RHE) of the oxygen evolution reaction (OER). Thus, substituting the OER with the UOR can effectively reduce the voltage required for electrolysis. Transition metal phosphates (TM-Pi), with their unique physical properties, can partly replace precious metal catalysts and hold great application potential. However, further modification is necessary to enhance their catalytic activity and stability. Therefore, this study prepared a coral-like cluster Co/Zn-Pi@NF (Pi represents phosphate) catalyst, which was grown in situ on nickel foam (NF) using the constant current electrodeposition method. The catalyst exhibited superior catalytic performance in 1M KOH, with the required overpotentials for the hydrogen evolution reaction (HER) and OER reaching 10mA·cm-2 being 36.6mV and 343.4mV, respectively. In 1M KOH containing 0.5M urea, the urea oxidation potential was only 1.4V, which remained stable for 60hours. The Co/Zn-Pi@NF nanoparticles were used as the anode and cathode for water-urea electrolysis, and the electrolysis voltage was 1.43V at a current density of 10mA·cm-2, which was 290mV lower than that of electrolyzed water. This study demonstrates that zinc-cobalt bimetallic phosphate can be used as a dual-function electrocatalyst for hydrogen evolution and urea oxidation.

Electrodeposited NiFeCoMoW High-Entropy Alloys with Nanoscale Amorphous Structure as Effective Hydrogen Evolution Electrocatalysts

Electrodeposited NiFeCoMoW High-Entropy Alloys with Nanoscale Amorphous Structure as Effective Hydrogen Evolution Electrocatalysts

Design of NiPS3/MoS2/rGO hybrid electrocatalyst for electrochemical hydrogen evolution

The design and development of efficient electrocatalysts for hydrogen evolution reaction is presently a pressing task to overcome future energy demands. In the present study a hybrid layered compound NiPS3/MoS2/rGO (NMR) is investigated as an electrocatalyst for hydrogen evolution reaction (HER). The metal trichalcogenidophosphates (MTPs), transition metal dichalcogenides and reduced graphene oxide materials based electrocatalysts are promising material for HER. The hybrid layered compound NMR displays good electrocatalytic activity in acidic medium in comparison to its counterparts MoS2/rGO and NiPS3/rGO with an overpotential and Tafel slope of 152 mV vs RHE and 75 mV/dec, whereas MoS2/rGO and NiPS3/rGO shows an overpotential of 206 mV and 223 mV vs RHE with a Tafel slope value of 146 mV/dec and 154 mV/dec respectively. The hybrid electrocatalyst exhibited high stability up to 1000 cycles with a stable current. The high HER activity of NMR is attributed to synergistic effect of electrocatalysts where P and S of NiPS3 acts as an appropriate hydrogen adsorption sites and catalytically active Mo edge sites of MoS2 with high charge carrier property of rGO contributed to enhanced hydrogen evolution reaction.

Rh–Ni(OH)2/NF via hydrolysis galvanic replacement of boride: Unveiling an exceptional electrocatalyst for high-current alkaline hydrogen evolution

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 RhCl3 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.

Integrating Multiple Strategies Using Biotechnology to Design High‐Performance Electrocatalysts for Hydrogen and Oxygen Evolution

AbstractCombining multiple design strategies often enhances catalyst performance but usually comes with high costs and low reproducibility. A technique that enhances catalyst performance in multiple strategies is urgently needed. Herein, a novel bioregulation technique is introduced, allowing simultaneous control over morphology, particle size, doping, interface engineering, and electronic properties. Bioregulation technique utilizes the soluble extracellular polymer from Aspergillus niger as a templating agent to construct high‐performance catalysts for hydrogen and oxygen evolution reaction (HER and OER). This technique controls catalyst morphology, introduces biological N and S doping, and regulates the electronic structure of the catalyst surface. Biomolecule modification enhances surface hydrophilicity, and the nanostructure increases surface roughness and gas‐release efficiency. Theoretical calculations show that the bioregulation technique shortens the d/p‐band center, optimizing reaction intermediate adsorption and desorption. The Bio‐Pt/Co3O4 catalyst with trace Pt on the surface, designed with these strategies, achieves HER (η10 of 42 mV), OER (η10 of 221 mV), and overall water‐splitting performance (1.51 V at 10 mA cm−2), maintaining stability for over 50 h, outperforming most Pt‐based catalysts. Notably, using spent lithium‐ion battery cathodes leachate, rich in Co2⁺, successfully replicates the experiment. This approach holds promise as a mainstream method for synthesizing high‐performance materials in the future.

Review on Recent Advances of Nickel Sulfide Nano Electrocatalysts for Hydrogen Evolution

AbstractHydrogen is an important energy carrier without carbon emissions. To achieve a carbon‐neutral world, the demand for hydrogen is very significant. In the process of producing green hydrogen, water splitting using electrocatalysts is a desirable process among many methods. The ideal electrocatalyst for hydrogen evolution is the platinum group of metals; however, the limitations of high cost and low abundance hinder large‐scale hydrogen production. Hence, researchers are trying to develop materials from more abundant and less expensive. Hence, in this review, we focus on the fundamental principles of hydrogen evolution reaction (HER) and various synthesis methods and strategies. From the material perspective, we focus on nickel sulfide‐based nanomaterials of different phases during the last four years of development. We compared the electrocatalyst parameters concerning the synthesis methods and strategies chosen. Finally, we have also discussed future challenges. Ultimately, by synthesizing the collective knowledge amassed in the field of HER research, this review endeavors to offer a comprehensive resource for researchers, engineers, and policymakers striving to advance hydrogen‐based energy technologies. In doing so, we aspire to foster continued innovation and collaboration toward realizing a sustainable energy future powered by hydrogen.

Recent Advances on Two-Dimensional Nanomaterials Supported Single-Atom for Hydrogen Evolution Electrocatalysts.

Water electrolysis has been recognized as a promising technology that can convert renewable energy into hydrogen for storage and utilization. The superior activity and low cost of catalysis are key factors in promoting the industrialization of water electrolysis. Single-atom catalysts (SACs) have attracted attention due to their ultra-high atomic utilization, clear structure, and highest hydrogen evolution reaction (HER) performance. In addition, the performance and stability of single-atom (SA) substrates are crucial, and various two-dimensional (2D) nanomaterial supports have become promising foundations for SA due to their unique exposed surfaces, diverse elemental compositions, and flexible electronic structures, to drive single atoms to reach performance limits. The SA supported by 2D nanomaterials exhibits various electronic interactions and synergistic effects, all of which need to be comprehensively summarized. This article aims to organize and discuss the progress of 2D nanomaterial single-atom supports in enhancing HER, including common and widely used synthesis methods, advanced characterization techniques, different types of 2D supports, and the correlation between structural hydrogen evolution performance. Finally, the latest understanding of 2D nanomaterial supports was proposed.

Complexes of a Noncyclic Carbazole-based N5-donor Schiff base: Structures, Redox, EPR and Poor Activity as Hydrogen Evolution Electrocatalysts.

A new noncyclic pentadentate N5-donor Schiff-base ligand, HL2Etpyr (1,1'-(3,6-ditert-butyl-9H-carbazole-1,8-diyl)bis(N-(2-(pyridin-2-yl)ethyl)methanimine)), prepared from 1,8-diformyl-3,6-ditertbutyl-carbazole (HUtBu) and two equivalents of 2-(2-pyridyl)ethylamine, along with four tetrafluoroborate complexes, [MIIL2Etpyr](BF4), where M = Co, Ni, Cu, and Zn, and two [CoIIL2EtPyr]·1/2[CoIIX4] complexes where X = NCS or Cl, isolated as solvates, are reported. All six complexes were structurally characterized, revealing the cations to be isostructural, with M(II) in a trigonal bipyramidal N5-donor environment. Only the Zn(II) complex is fluorescent. Cyclic voltammograms of [MIIL2Etpyr](BF4) in MeCN reveal reversible redox processes at positive potentials: 0.61 (Zn), 0.62 (Cu), 0.57 (Ni), and 0.25 V (Co), and for the cobalt complex a second quasi-reversible process occurs at 0.92 V vs Fc+/Fc. EPR data for the first oxidation product clearly demonstrate that the Zn complex undergoes a ligand centered oxidation, and support this being the case for the Ni and Cu complexes, although this is not definitively shown. After both oxidations the EPR data shows that the Co complex is best described as a low spin Co(III)-ligand radical. In the presence of 80 mM acetic acid, controlled potential electrolysis carried out on [MIIL2Etpyr](BF4) at -1.68 V in MeCN shows some electrocatalytic hydrogen evolution reaction (HER) performance in the order Ni(II) > Cu(II) > Co(II) - but the control, Ni(II) tetrafluoroborate, is more active than all three of the complexes.

Dual active sites engineering of electrocatalysts for alkaline hydrogen evolution

Dual active sites engineering of electrocatalysts for alkaline hydrogen evolution

Synergistic heterostructural interface of CoP and WC for high-performance wide pH-universal hydrogen evolution electrocatalysis

The development of cost-effective catalysts with high activity and stability over a wide pH range is urgent, but there are great challenges in the selection and design of catalyst materials. In this work, cobalt phosphide nanoparticles were modified onto tungsten carbide nanowire arrays (CoP@WC/CC) on carbon cloth substrate by a two-step method. The construction of CoP@WC heterostructure results in the downward shift of the d-band center, which optimizes the adsorption energy of catalyst and reaction intermediates. Meanwhile, the synergistic effect of CoP and WC contributes to the alkaline HER kinetic process. In addition, binder-free self-supporting nanoarray have excellent electrical conductivity, large specific surface area and strong structure, which is conducive to charge/matter exchange and catalyst stability. The results show that CoP@WC/CC can effectively drive HER over a wide pH range and exhibit better catalytic performance than the single component control sample. In 0.5 M H2SO4 and 1 M KOH, CoP@WC/CC can drive the current density of 10 mA cm−2 with only 52 and 70 mV, while showing excellent stability without obvious performance degradation during 100 h of constant current test. A proton exchange membrane water electrolysis (PEMWE) using CoP@WC/CC catalyst operates stably for 200,000 s at 30 mA cm−2. This study provides a new reference for the design and development of high efficiency, low cost and wide pH-universal hydrogen evolution electrocatalysts.

A strategy to reutilize silver nanoparticles on silicon nanowires via photocathodic activation for enhanced and sustainable hydrogen evolution

The development of electrodes for hydrogen evolution via water splitting in a neutral electrolyte is highly desirable, especially considering that natural water resources such as seawater typically have a neutral pH. In this study, silicon nanowires (SiNWs) arrays with uniform silver (Ag) decoration are prepared as a cathode material, which exhibits excellent and stable electrochemical performance for neutral water electrolysis. Ag ions, utilized in the preparation of SiNWs through metal-assisted chemical etching technique, are retained and decorated within the SiNWs array without undergoing a dissolution process, referred to as Native SiNWs. Remained Ag+ ions on the SiNWs are activated photocathodically and reduced to Ag0, resulting in a significantly enhanced performance as an electrocatalyst for hydrogen evolution reaction (HER). Hence, this photocathodic activation of Native SiNWs (PCA-Native SiNWs) eliminates the need for additional cocatalyst deposition for HER, utilizing the Ag ions employed in the SiNWs preparation process. This enhancement in HER activity is exclusively observed by photocathodic activation, not by cathodic activation without light irradiation, indicating the crucial role of photoelectrons in SiNWs under light irradiation for the activation. Additionally, the nanowire structure serves as an ideal platform for Ag nanoparticles, providing sufficient surface area, resulting in excellent dispersion and an increased number of active sites. Furthermore, PCA-Native SiNWs demonstrates outstanding electrochemical stability for over 60 h, with no significant reduction in current density or structural degradation in a neutral electrolyte. Several characterizations and electrochemical analyses have been conducted to elucidate the in-situ decoration of Ag nanoparticles on SiNWs and investigate the surface chemistry for the activation mechanism. This work introduces a new perspective on using Ag-decorated SiNWs directly as an electrocatalyst for effective hydrogen evolution in a neutral media.

Electrodeposition of Non-Noble High-Entropy Alloys for Effective Hydrogen Evolution Electrocatalysts

As society works towards reducing its carbon footprint, various sectors such as energy, steelmaking and fertilizer production have begun to look increasingly towards decarbonization. Hydrogen production through electrolysis, when linked to renewables (solar, wind), provides a promising low-emission alternative as an energy carrier and chemical feedstock. With the decreasing cost of said renewables, greater focus is now on the capital cost of the electrolyser, and particularly the membrane/electrode structures. Conventional Proton Exchange Membrane (PEM) electrolysers rely on the use of electrocatalysts made with expensive noble metals such as platinum, ruthenium, and palladium [1]. Anion Exchange Membrane (AEM) electrolysers present an effective means of alkaline water splitting with low carbon emissions and can effectively utilize non-noble metal electrocatalysts for the Hydrogen Evolution Reaction (HER). A novel class of materials, High-Entropy Alloys (HEAs), made of non-noble metals or with reduced noble metal content have shown great promise as active electrocatalytic materials [2]. HEAs are typically defined as metal alloys made of five or more constituent elements each comprising at least 5% of the total material [3]. Having such a large number of principal alloying elements can lead to enhanced phase stability due to an increased configurational entropy, have unique chemical clustering, and can help prevent degradation of the material in harsh environments [2]. Additionally, the large lattice parameter mismatch between constituent elements can result in a high degree of strain which can help shift electronic states in a way that is favourable to hydrogen electrocatalysis [4]. These properties along with the so called “cocktail effect,” whereby combining multiple elements can result in unexpected synergistic interactions, makes HEAs uniquely suited to electrocatalytic applications [5].In this work, we investigate the electrocatalytic performance of electrodeposited FeNiCoMoW HEAs. The goal is to combine three hyper-d transition metals with two hypo-d transition metals to alter the electronic structure and improve electrocatalytic performance. Using chronoamperometric measurements, the Tafel slopes for FeNiCoMoW HEAs electrodeposited at pH 5, 6 and 7 were determined, with the pH 5 HEA demonstrating the smallest average Tafel slope of approximately 83 mV/dec. Compared to some electrodeposited binary alloys reported on in the literature, this marks an improvement and may be the result of unexpected interactions within the compositionally complex alloy. In the FeNiCoMoW HEA, the magnitude of the Tafel slope increased in tandem with the electrochemically active surface area (ECSA) as determined by Cyclic Voltammetry (CV) which suggests that the composition may be more important for improving performance. As the pH of the electrodeposition solution increased, the amount of cobalt in the as-deposited HEA decreased while the amounts of molybdenum and tungsten remained constant. The composition of nickel and iron appeared to vary inversely, reaching a maximum and minimum respectively at pH 6. From these results it seems that maximizing cobalt content and minimizing nickel content could potentially help to improve HER performance in the FeNiCoMoW system.

Bio-Inspired histidine-based copper complex: An efficient and robust electrocatalyst for electrochemical hydrogen evolution

The quest for an efficient and sustainable electrocatalyst for hydrogen evolution reaction (HER) using earth-abundant elements is crucial for cost-effective and environmentally friendly hydrogen production. While many catalysts show good activity and stability in strongly basic conditions, fewer materials are effective under neutral conditions, which are more practical for electrolyzer operations. This study introduces a dinuclear copper catalyst, [Cu2(μ-OH) (μ-NO3) (L)2], where L is the Schiff base ligand derived from salicylaldehyde and histidine amino acid (Complex 1), for HER in both aqueous and non-aqueous environments. In non-aqueous conditions, with acetic acid as a proton source, the catalyst exhibits outstanding HER performance, achieving an overpotential of 170 mV. At an acid concentration of 0.086 M, it achieves a catalytic current of ∼17.5 mA cm−2 at an overpotential of 0.52 V. Remarkably, in fully aqueous neutral conditions, Complex 1 reaches a significant current density with an ic/ip ratio of ∼82 at a scan rate of 1.0 V s−1, and an apparent rate constant (kobs) for electrocatalytic HER of ∼13,200 s−1. The catalyst also shows excellent activity in 0.1 M H3PO4, with low overpotentials of ∼150 mV at 2.0 mA cm⁻2 and 270 mV at 10.0 mA cm⁻2. In controlled potential electrolysis (CPE), the catalyst maintains stable catalytic currents of 25 mA cm⁻2 and 75 mA cm⁻2 for 18–28 h at a potential of 0.590 V vs. RHE in neutral and acidic conditions, respectively, without noticeable decrease in catalytic current. Detailed characterizations confirm the molecular integrity of the catalyst and its predominantly homogeneous catalytic mechanism.

Antimony-assisted controlled growth of PtSe2 ribbon arrays for enhanced hydrogen evolution reaction

In this study, we report the successful synthesis of few-layer parallel PtSe2 ribbons on an Au foil employing a surface melting strategy via the chemical vapor deposition growth method at 650 °C. The controlled formation of parallel ribbons was directed by the Au steps generated through antimony treatment. These ribbons exhibit an average length of exceeding 100 μm and a width of approximately 100 nm across a substantial area. Electrocatalysis measurements showcase the catalytic performance of PtSe2 ribbons grown on Au foil, which can be further augmented through subsequent oxidation treatment. This investigation introduces an effective growth method for few-layer ribbons at low temperatures and broadens the scope of employing the substrate-guided strategies for the synthesis of one-dimensional materials. Additionally, it underscores the potential of PtSe2 ribbons as an electrocatalyst for hydrogen evolution.

Regulating the electronic structure of Pt SAs-Ni2P for enhanced hydrogen evolution reaction

The single atom catalysts (SACs) show immense promise as catalytic materials. By doping the single atoms (SAs) of precious metals onto substrates, the atomic utilization of these metals can be maximized, thereby reducing catalyst costs. The electronic structure of precious metal SAs is significantly influenced by compositions of doped substrates. Therefore, optimizing the electronic structure through appropriate doping of substrates can further enhance catalytic activity. Here, Pt single atoms (Pt SAs) are doped onto transition metal sulfide substrate NiS2 (Pt SAs-NiS2) and phosphide substrate Ni2P (Pt SAs-Ni2P) to design and prepare catalysts. Compared to the Pt SAs-NiS2 catalyst, the Pt SAs-Ni2P catalyst exhibits better hydrogen evolution catalytic performance and stability. Under 1 M KOH conditions, the hydrogen evolution mass activity current density of the Pt SAs-Ni2P catalyst reaches 0.225 A mgPt–1 at 50 mV, which is 33 times higher than that of commercial Pt/C catalysts. It requires only 44.9 mV to achieve a current density of 10 mA cm−2. In contrast, for the Pt SAs-NiS2 catalyst, the hydrogen evolution mass activity current density is 0.178 A mgPt–1, requiring 77.8 mV to achieve a current density of 10 mA cm−2. Theoretical calculations indicate that in Pt SAs-Ni2P, the interaction between Pt SAs and the Ni2P substrate causes the Pt d-band center to shift downward, enhancing the H2O desorption and providing optimal H binding sites. Additionally, the hollow octahedral morphology of Ni2P provides a larger surface area, exposing more reactive sites and improving reaction kinetics. This study presents an effective pathway for preparing high-performance hydrogen evolution electrocatalysts by selecting appropriate doped substrates to control the electronic structure of Pt SAs.

Heterostructured ZnIn2S4/Ni2P/NiS on Nickel Foam as Self-Supported pH-All Electrocatalysts for Hydrogen Evolution

Heterostructured ZnIn₂S₄/Ni₂P/NiS on Nickel Foam as Self-Supported pH-All Electrocatalysts for Hydrogen Evolution

Facile electrodeposited sandwich-like CuSx/MnSx electrocatalyst for efficient hydrogen evolution in seawater splitting

This study investigates a sandwich-like CuSx/MnSx electrode fabricated through electrodeposition technique on nickel foam (NF) substrate for hydrogen evolution reaction (HER) in seawater splitting. The synthesized electrode exhibits plenty of active sites, substantial specific surface area, and a distinctive morphology reminiscent of a tuberose-type nanostructure. Moreover, synergistic activity between the copper and manganese components enhances the rate of electron transfer process, thereby augmenting the electrocatalytic performance. Partial oxidation serves to increase active sites and control the morphology of the nanoparticles. The optimized electrode exhibits a minimal overpotential of 144 mV at 10 mA/cm2 for saline water splitting. The Tafel slope of 197 mV/dec and a transfer coefficient (α) of 0.3 indicate that the rate-determining step for the HER is likely the initial Volmer reaction. A higher electrochemical surface area (ECSA) of 2268 cm2, a solution resistance of 0.84 Ω, and a charge transfer resistance of 5.18 Ω suggest improved ion diffusion in the synthesized electrode. The electrocatalytic performance was also investigated by carrying out experiments with varying alkalinity in natural seawater electrolytes. The catalyst demonstrated robust stability for HER in natural seawater splitting with constant current density after 50 h of chronoamperometric analysis. The facile electrodeposited electrocatalyst exhibits energy-efficient and sustainable performance, effectively catalyzing reactions in a seawater-based electrolyte during the HER.

Dual-Intermetallic Heterostructure on Hierarchical Nanoporous Metal for Highly Efficient Alkaline Hydrogen Electrocatalysis.

Constructing well-defined active multisites is an effective strategy to break linear scaling relationships to develop high-efficiency catalysts toward multiple-intermediate reactions. Here, dual-intermetallic heterostructure composed of tungsten-bridged Co3W and WNi4 intermetallic compounds seamlessly integrated on hierarchical nanoporous nickel skeleton is reported as a high-performance nonprecious electrocatalyst for alkaline hydrogen evolution and oxidation reactions. By virtue of interfacial tungsten atoms configuring contiguous multisites with proper adsorptions of hydrogen and hydroxyl intermediates to accelerate water dissociation/combination and column-nanostructured nickel skeleton facilitating electron and ion/molecule transportations, nanoporous nickel-supported Co3W-WNi4 heterostructure exhibits exceptional hydrogen electrocatalysis in alkaline media, with outstanding durability and impressive catalytic activities for hydrogen oxidation reaction (geometric exchange current density of ≈6.62 mA cm-2) and hydrogen evolution reaction (current density of ≈1.45 A cm-2 at overpotential of 200 mV). Such atom-ordered intermetallic heterostructure alternative to platinum group metals shows genuine potential for hydrogen production and utilization in hydroxide-exchange-membrane water electrolyzers and fuel cells.