Hydrogen Evolution Reaction Performance Research Articles

Sustainable hydrogen production with synergistic electron transfer enhancement in nickel-based alkaline HER electrocatalyst empowered by graphene oxide

The hydrogen evolution reaction (HER) plays a crucial role in driving forward the transition to a hydrogen-based economy by providing a means to generate pure hydrogen. However, the efficient and cost-effective production of hydrogen via HER faces significant challenges, particularly at the cathode. To address these challenges, we produced a hybrid material – 2D graphene oxide (GO) sheets coated onto nickel sulfide (NiS) microspheres anchored on Ni Foam (GO@NiS/Ni Foam) using a straightforward synthesis technique. Our research highlights the significant influence of the interaction between GO and NiS on the performance of HER, attributed to the enhancement of electron transport at the interface. Furthermore, the GO@NiS/Ni Foam composite exhibits remarkable durability over extended periods, maintaining its superior functionality for up to 40 h of continuous operation. This underscores its potential for practical implementation in efficient water-splitting processes, offering a promising solution to the challenges hindering widespread adoption of hydrogen technology.

Optimizing Activity and Stability in AgCl‐CuO Electrocatalysts: Insights from Different Morphologies for Enhanced ORR Performance

Highly enduring and methanol‐tolerant electrocatalysts are pertinent to revolutionizing direct methanol fuel cell (DMFC) technologies. Transition metal‐based electrocatalysts are anticipated to rank among the remarkable electrocatalysts for boosting the sluggish Oxygen Reduction Reaction (ORR) kinetics. Herein, we report a facile approach to optimize the activity and stability of the AgCl‐CuO systems. The tailored Nano Particle‐Nano Rod (NP‐NR) and Nano Leaf (NL) like morphologies deliver remarkable bifunctional catalytic performance for oxygen reduction and hydrogen evolution reactions, sustained activity, and comparatively better stability for ORR. A meager shift of only 0.014 V and 0.024 V in the half‐wave potential is observed in the NP‐NR and NL structures, respectively, for the ORR even after 2500 cycles. Furthermore, both the AgCl‐CuO composite exhibits an excellent tolerance to methanol.

Application of Hydrogen Spillover to Enhance Alkaline Hydrogen Evolution Reaction

AbstractAlkaline water splitting has shown great potential for industrial‐scale hydrogen production. However, its broad application is constrained by hydrogen evolution reaction (HER) electrocatalysts, which struggle to achieve optimal current density at low overpotential. The utilization of the hydrogen spillover effect to augment the performance of HER represents a burgeoning area of research. Although previous studies mainly focused on hydrogen spillover in acidic media, the latest studies have shown that hydrogen spillover also exists under alkaline conditions, and its role in improving HER performance cannot be ignored. This review examines the mechanisms of HER under acidic and alkaline conditions, elucidating the distinctive behavior of hydrogen spillover in these environments and its influence on catalytic processes. At the same time hydrogen spillover characterization methods are systematically summarized, these technologies for understanding and control of hydrogen release process provides strong support. Finally, the recent electrocatalysts that enhance the catalytic performance of alkaline HER by hydrogen spillover effect are comprehensively sorted out and summarized. This review not only demonstrate the practical value of hydrogen spillover under alkaline conditions, but also provide new directions for future design and optimization of electrocatalysts.

NiMOF-Derived MoSe2/NiSe Hollow Nanoflower Structures as Electrocatalysts for Hydrogen Evolution Reaction in Alkaline Medium.

Metal-organic frameworks (MOFs) are crystalline porous materials for storage and energy conversion applications with three-dimensional pore structure, high porosity, and specific surface area, which are widely utilized in electrocatalysis. Herein, MoSe2/NiSe composites were synthesized by selenization reaction using NiMOF as the precursor. The composites were hollow nanoflower structures with a synergistic effect between MoSe2 and NiSe to promote rapid electron transfer, which exhibited good hydrogen evolution reaction performance in an alkaline medium. At a current density of 10 mA/cm2, the HER overpotential reaches 80 mV, the Tafel slope is 33.86 mV/dec, and the material has good stability, with polarization curves remaining essentially unchanged after 3000 cycles. These results indicate that the method has a promising application in the preparation of efficient and sustainable catalysts for hydrogen production in alkaline medium.

Boosting HER performance by using plasma prepared N-doped CNTs to support Pt nanoparticles

Developing highly-efficient and stable Pt-based catalysts towards alkaline hydrogen evolution reaction (HER) offers a promising strategy for future renewable energy. In this work, radio-frequency (RF) cold plasma-prepared N-doped MWCNTs were adopted to support Pt nanoparticles (NPs) (Pt/NCNTs) via pretreating MWCNTs with RF nitrogen plasma and combining with traditional thermal reduction method. The as-synthesized Pt/NCNT featured an ultra-small size of Pt NPs (1.5 nm) and plentiful doped nitrogen, exhibiting ultra-low overpotential of 28 mV@10 mA cm−2 and ultra-high mass activity of 3.2 A mg Pt−1@100 mA in 1 M KOH solution, which are superior to those of commercial 20 wt% Pt/C catalyst. This is because RF plasma can realize fast, high-efficient and specific N-doping structure of MWCNTs. The lone electron pairs of N species (mainly pyri-N and pyrr-N) on MWCNTs surface transfer to the empty orbitals of Pt NPs, forming a strong coordination effect between Pt and nitrogen, thereby boosting the alkaline HER catalytic performance.

Cutting-Edge PCN-ZnO Nanocomposites with Experimental and DFT Insights into Enhanced Hydrogen Evolution Reaction.

Polymeric carbon nitride (PCN) and PCN-ZnO nanocomposites are promising candidates for catalysis, particularly for hydrogen evolution reactions (HER). However, their catalytic efficiency requires enhancement to fully realize their potential. This study aims to improve the HER performance of PCN by synthesizing PCN-ZnO nanocomposites using melamine as a precursor. Two synthesis methods were employed: thermal condensation (Method 1) and liquid exfoliation (Method 2). Method 1 resulted in a composite with a 2.44 eV energy gap and reduced particle size, with significantly enhanced performance as a bifunctional electrocatalyst for simultaneous hydrogen and oxygen production. In contrast, Method 2 produced a nanocomposite with an enhanced surface area and a minor alteration in the band gap. In alkaline electrolytes, the PCN-ZnO0.4 nanocomposite synthesized with Method 1 exhibited high HER performance with an overpotential of 281 mV, outperforming pristine PCN (382 mV) and ZnO (302 mV), along with improved oxygen evolution reaction (OER) activity. Further analysis in a two-electrode alkaline electrolyzer using PCN-ZnO0.4 nanocomposite as both the anode and cathode demonstrated its promise as a bifunctional electrocatalyst. Density functional theory (DFT) calculations explained the enhanced catalytic activity of the PCN-ZnO nanocomposite, confirming that hydrogen evolution occurs through the Heyrovsky process, consistent with experimental results. Notably, the solar-to-hydrogen (STH) efficiency of the PCN-ZnO nanocomposite was four times greater, at 21.7% compared to 5.2% for the PCN monolayer, underscoring its potential for efficient solar-driven hydrogen production. This work paves the way for future advancements in the design of high-performance electrocatalysts for sustainable energy applications.

In-situ synthesis of bifunctional N-doped CoFe₂O₄/rGO composites for enhanced electrocatalysis in hydrogen and oxygen evolution reactions

The development of cost-effective and efficient materials for electrochemical water splitting using non-noble metal oxide is a promising strategy to promote clean energy and mitigate environmental issues. In this study, we synthesized N-doped CoFe2O4 (NCF) and various wt% rGO-loaded N-doped CoFe2O4 (x = 1 %, 3 %, and 5 %; denoted as NCFRx) using a hydrothermal method. Subsequently, the NCF and NCFR3 samples were annealed at four different temperatures (y = 550, 600, 650, and 700 °C; denoted as NCFR3-y). FE-SEM, TEM, and XPS studies revealed a strong interface between rGO nanosheets and N-doped CF, acting as electron transport carriers that enhance performance in hydrogen and oxygen evolution reactions (HER and OER). The electrochemical evaluation of the prepared materials was carried out in a 1.0 M KOH electrolyte. The nickel foam (NF) electrode supported by the NCFR3–650 composite demonstrated excellent and stable electrocatalytic performance with a minimum overpotential of 73 mV and 170 mV at a current density of 10 mA/cm2 for HER and OER, respectively, and achieved excellent faradaic efficiencies of 91.01 % for OER and 90.48 % for HER. These results confirmed that the NCFR3–650@NF composite catalyst was comparable to standard Pt/C and IrO2, exhibiting lower overpotential and Tafel slope at a current density of 10 mA/cm2. The double layer capacitance (Cdl) of NCFR3–650@NF (7.70 mF/cm2) was higher than that of other electrocatalysts, indicating a large electrochemically active surface area. The structural properties of NCFR3–650@NF contributed to improved stability during long-term HER and OER analysis. Therefore, the developed NCFR3–650@NF electrocatalyst is a promising alternative to noble metal-centered systems for water splitting, offering overall high efficiency.

Computational screening of single-atom transition metals on boron-rich boron nitride nanosheets for efficient hydrogen evolution catalysis in all pH range.

Low-cost and high-efficiency catalysts are of crucial importance for the electrocatalytic hydrogen evolution reaction (HER). Two-dimensional (2D) boron nitride (B-N) compounds formed by the combination of boron and nitrogen atoms of group III and V elements are promising candidates for electrocatalytic HER due to their significant electronic properties. Hence, an electrocatalyst is computer-aided designed with isolated single atoms of 3d, 4d, and 5d transition metals supported on 2D B-N (B2N, B5N3, and B7N5) monolayers to fabricate single-atom catalysts (SACs) with an excellent HER performance. Moreover, pH modulations are considered to improve the HER activity theoretically based on first-principles calculation. Our results indicate that B-N compounds surface doping with transition metal atoms can effectively enhance the HER catalytic performance over a wide range of pH. Among all SACs studied, Co-, Ti-, V-, Nb-, Ru-, Tc-, Zr-, and Os-embedded B2N, Sc-, Cr-, Mn-, Ti-, and Y-embedded B5N3, and Sc- and Mn-embedded B7N5 have excellent catalytic activity under acidic conditions, while Mo-, Ir-, Re-, Ta-, and W-embedded B2N and Ti- and Fe-embedded B7N5 show high catalytic activity under alkaline conditions. Interestingly, Hf@B2N and V@B5N3 systems exhibit promising catalytic activity under acidic, neutral, and alkaline conditions. Our work offers cost-effective candidates with a wide pH range HER performance for exploring ideal electrocatalysts.

Silver Nanowire Aerogel Support Promotes Stable Hydrogen Evolution Reaction at High Current Density.

The stability of electrocatalysts during the hydrogen evolution reaction (HER) is vital for efficient production of hydrogen energy. Herein, we demonstrate that silver nanowire aerogel-based support (AABS) could facilitate the construction of HER catalysts with extraordinary long-term stability. A full nanostructure catalyst of nickel phosphide based formed on AABS (Ni2P-Ni5P4@AABS) was prepared to achieve an overpotential of 687 mV (without iR compensation) for HER at the current density of 1 A cm-2 in 0.5 M H2SO4. Excitingly, the stable HER performance was kept for 42 days during the long-term stability (i-t) test at high current density (0.5-1 A cm-2). The excellent HER performance of the Ni2P-Ni5P4@AABS catalyst is attributed to rapid electron transport pathways, numerous more accessible active sites, and support induced enhanced catalytic activity. The support effect was highlighted by a proposed phenomenological two-channel model for electron transport, which provides fresh insights into the design strategy for energy storage and delivery.

In situ construction of W-doped Co-P electrocatalyst by electrodeposition for boosting alkaline water/seawater hydrogen evolution reaction

The development of an efficient yet cost-effective non-precious electrocatalyst for the hydrogen evolution reaction (HER) in alkaline water and seawater systems remains a formidable obstacle to the large-scale production of hydrogen energy, stemming from the sluggish kinetics of electron transfer reactions during the HER process. In this article, an amorphous Co-P-W electrocatalyst on nickel foam is prepared using a brief cyclic voltammetry (CV) electrodeposition method. The optimized Co-P-W electrocatalyst exhibits excellent electrocatalytic performance for HER, which only requires overpotentials of 59 and 143 mV to achieve a current density of 10 mA cm−2 in alkaline water (1.0 M KOH) and alkaline seawater (1.0 M KOH + natural seawater), respectively, and remarkable stability and durability. The improved HER performance of the Co-P-W electrocatalyst is attributed to the introduction of W, which modulates the electronic structure of Co and P, optimizes the adsorption/dissociation of H2O, and reduces the charge transfer resistance of the Co-P electrocatalyst, thus improving the kinetics of the HER. Furthermore, the W-doping significantly enhances the hydrophilicity of the Co-P electrocatalyst, which favors rapid and thorough penetration of electrolytes into the electrocatalyst, facilitating the formation of a highly accessible reaction interface, ultimately resulting in excellent HER activity. Our findings demonstrate the feasibility of designing an efficient, durable, and scalable electrocatalyst to significantly boost HER efficiency for practical water electrolysis.

NiCoP/CoP2 nanoparticles supported on sugarcane bagasse carbon as the electrocatalyst with excellent catalytic performance towards the hydrogen evolution reaction

Sugarcane bagasse carbon (SCBC) was synthesized and used to support NiCoP/CoP2 nanoparticles (NiCoP/CoP2-SCBC), and its electrocatalytic performance for the hydrogen evolution reaction (HER) was investigated and compared with that of NiCoP/CoP2 nanoparticles and NiCoP/CoP2 nanoparticles supported on carbon black (NiCoP/CoP2-C). Impressively, NiCoP/CoP2-SCBC shows the best electrocatalytic performance for HER with an over-potential of 159.5 mV at 10 mA cm-2 and a Tafel slope of 67.24 mV dec-1, along with the excellent stability. This outstanding performance is partly attributed to the abundant hydroxyl functional groups in SCBC, which can make the catalyst have better dispersion and a higher proportion of Ni2+. In addition, SCBC can lead to more defects in NiCoP/CoP2, and SCBC contains a large number of P elements, which can increase the catalytic active sites and contribute to the fast HER process to some degree.

Self-Standing Mo/MoO2 Porous Flake Arrays for Efficient Hydrogen Evolution Reaction in High-pH Media.

The alkaline hydrogen evolution reaction (HER) is limited by scarce proton availability, resulting in slower reaction kinetics compared to those under acidic conditions. Enhancing the local chemical environment of protons on the catalyst surface can improve the intrinsic reaction kinetics. Here, we design a Mo/MoO2 metallic heterojunction that creates an acidic-like environment with a proton-rich surface, significantly enhancing HER performance in alkaline electrolytes, as confirmed by in situ spectroscopy and electrochemical analysis. A self-standing Mo/MoO2 catalytic electrode is fabricated via a controlled pyrolysis-reduction strategy. This electrode exhibits exceptional HER activity, with low overpotentials of 65 mV at 10 mA cm-2 and 315 mV at 500 mA cm-2, a Tafel slope of 38.2 mV dec-1, and stability exceeding 60 h at -300 mA cm-2 in alkaline solution. The porous flake array structure of the Mo/MoO2 heterojunctions enhances the adjacent hydronium (H3O+) concentration, resulting in a ΔGH* value of 0.15 eV and a water dissociation energy barrier of 0.37 eV in an alkaline medium. The successful preparation of a large-area electrode (2 cm × 2 cm) demonstrates the scalability of this approach for fabricating molybdenum-based catalytic electrodes with enhanced HER activity in alkaline environments.

Unveiling the degradation mechanism of cathodic MoS2/C electrocatalysts for PEMWE applications

Molybdenum dichalcogenides (MoS2) are promising non-noble alternatives to replace platinum (Pt) for Hydrogen Evolution Reaction (HER) electrocatalysis in Proton Exchange Membrane Water Electrolyzers (PEMWE). The knowledge acquired on this class of catalyst for hydrodesulfurization (HDS) reactions has enabled significant advances in designing active MoS2 for HER. However, the stability of MoS2 in the dynamic operating conditions of a PEMWE coupled to renewable energy sources is often overlooked in the literature and is the focus of the present work. Herein, using nano slabs of 2H MoS2 supported on high surface area carbon, we dynamically monitored Mo dissolution trends both under HER conditions and at more anodic potentials to mimic start-ups and shut-downs of a PEMWE device. We report minimal Mo dissolution under HER conditions but it continuously increased with higher electrode potentials. In particular, Mo dissolution peaked during the irreversible oxidation from Mo(IV) to Mo(VI) starting at E = 0.7 VRHE which in turn fully annihilates HER activity. Since no change in Mo and S surface composition was observed, the decline in HER activity was attributed to the continuous exfoliation of the 2D MoS2 stacked layers induced by oxidation/dissolution of Mo. Additionally, our findings indicate that Mo cations can redeposit onto the cathode catalytic layer, forming a Mo blue film primarily composed of Mo(VI) species. This redeposition hampers HER performance by blocking catalytic sites and diminishing the catalyst's overall efficiency. These insights demonstrate the need to avoid excursions above E = 0.6 VRHE for the safe use of MoS2 cathode catalyst in PEMWE.

Synergy of S doping and defect construction in holey ultra-thin g-C3N4 nanosheets for improved photocatalytic hydrogen production from water

Combining the advantages of multiple strategies including morphology control, atom doping, and defect construction, the photocatalytic hydrogen evolution reaction (HER) performance of graphitic carbon nitride (g-C3N4) may be boosted significantly. Herein, holey ultra-thin g-C3N4 nanosheets (CNS-x, x = H, O, N) modified with structural vacancies and sulfur (S) dopant are synthesized through a straightforward method involving the pyrolysis of thiocyanuric acid under various gas atmospheres. The textural properties, type and concentration of structural defect, and S doping level are significantly influenced by the gas atmosphere. Remarkably, CNS-H with C, N dual defects and S-dopant exhibits the HER rate of 46.59 mmol·g−1·h−1, which is 16.68 times higher than that of bulk g-C3N4. The corresponding apparent quantum yields are 17.24 % at 420 nm and 1.90 % at 520 nm. The enhanced HER performance of CNS-H can be attributed to the combined effect of improved charge separation, extended photoabsorption, and optimized properties of the platinum cocatalyst.

Urea-induced low crystallization of Rh nanoparticles for efficient H2 production

Developing highly efficient catalysts for the hydrogen evolution reaction (HER) is crucial for advancing renewable hydrogen energy technologies. Heterophase nanomaterials have shown great promise in catalysis, owing to the synergistic effect among various phases and the abundance of active sites located at the phase boundaries or interfaces. However, achieving precise control over these phase structures during synthesis remains a significant challenge. In this work, we explored a one-pot synthesis method for amorphous/crystalline heterophase Rh nanoparticles, with crystallinity tunable by adjusting the quantity of urea and reaction duration. Due to the increased electrochemical active sites, enhanced electron transport, the resulting amorphous/crystalline heterophase Rh exhibits superior HER activities in both acidic (with an overpotential of 27 mV) and alkaline media (with an overpotential of 21 mV), surpassing that of commercial Pt/C and crystalline Rh. Theoretical calculations indicate that the amorphous/crystalline structure reduces the kinetic barrier for water splitting and optimizes adsorption free energy of hydrogen (ΔGH∗), thereby enabling the catalyst to exhibit significantly enhanced HER performance. This exploration offers a valuable reference for designing amorphous/crystalline heterophase structures and demonstrates the great potential of phase engineering strategy in the development of electrocatalysts.

Sparkling Synergy: Enhancing Hydrogen Evolution with a Mesoporous CoP/FeP Interface.

The reaction kinetics is predominantly determined by the surface and interface engineering of electrocatalysts. Herein, we demonstrate the growth of cobalt monophosphide and iron monophosphide (CoP/FeP) with an effective solid interface. The surface of CoP/FeP is mesoporous, which is obtained by phosphidizing mesoporous CoFe2O4. The CoP/FeP electrode exhibits substantially superior hydrogen evolution reaction (HER) performance compared to CoP and FeP. The overpotentials (η) required to generate 10 mA cm-2 are determined to be around 98 mVRHE (CoP/FeP), 220 mVRHE (FeP), and 265 mVRHE (CoP) in an acidic electrolyte. The exchange current density and Tafel slopes suggest that CoP/FeP has better redox properties and kinetic abilities compared to FeP and CoP. Furthermore, the CoP/FeP electrode exhibits reduced electrochemical impedance and superior surface charge transport characteristics in comparison to both the CoP and FeP electrodes. In addition to having a greater number of catalytically active sites, the turnover frequency of CoP/FeP is approximately 2 and 5 times higher than that of FeP and CoP, respectively. The CoP/FeP electrode maintains a consistent current density of around 25 mA cm-2 for a continuous period of 24 h during the HER, attesting to the excellent durability of the CoP/FeP electrode. In addition, a relationship between differential hydrogen adsorption energy (ΔEH), the corresponding Gibbs free energy change (ΔGH), and the hydrogen coverage on distinct surfaces, namely, CoP, FeP, and CoP/FeP, is established. The calculation findings show that the CoP/FeP surface, which is predominantly exposed with CoP, exhibits the highest catalytic potential for the HER. The estimation of the specific HER activity of the electrodes, normalized to the electrochemically active surface area, corroborates the calculation findings.

Controlled synthesis of the M doped (M = Fe, Cu, Zn, Mn)-Co4S3/Ni3S2 catalyst with high electrocatalytic performance for hydrogen evolution reaction in seawater and urea

Electrolysis of seawater is a promising method for producing hydrogen, but sluggish reaction kinetics and electrolyte containing corrosive ions limit its development. In this work, a series of M doped (M = Fe, Cu, Zn, Mn)-Co4S3/Ni3S2 catalyst has been prepared on Ni foam by hydrothermal method with excellent seawater and urea splitting performance. The unique 3D porous structure provides a large number of active sites for the catalyst, which has strong catalytic activity. Fe-Co4S3/Ni3S2 electrode showed excellent hydrogen evolution reaction (HER) catalytic activity in 1 M KOH + seawater and 1 M KOH + 0.5 M urea, driving a current density of 10 mA cm−2 at a low overpotential of 81 and 66 mV. In addition, Fe-Co4S3/Ni3S2 electrode also shows strong stability in 15 h stability test. The results show that although the impurity ions in seawater affect the activity of catalyst, the corrosion resistance of catalyst also improves the catalytic activity and stability. Density functional theory calculations show that this Fe-Co4S material exhibits the optimal Gibbs free energy of hydrogen, the introduction of this Ni3S2 material enhances the electrical conductivity of the material, and the synergistic catalysis of the two materials promotes the optimal hydrogen production performance of the Fe-Co4S3/Ni3S2 material. This work provides a novel understanding for the research of catalysts used in the electrolysis of seawater and urea.

Polyoxometalate-derived anti-aggregation MoC nanoparticles for efficient hydrogen evolution in basic and acidic media

As a cost-effective alternative to Pt-based catalysts, molybdenum carbide (MoC) exhibits considerable potential for catalysing hydrogen evolution reaction (HER) in both alkaline water electrolyzers and proton exchange membrane water electrolyzers. However, achieving ampere-level current densities at low overpotentials remains challenging for MoC-based electrocatalysts. In this study, we utilized electrospinning technology followed by a subsequent heat treatment to successfully synthesize monodisperse MoC nanoparticles (approximately 4.3 nm) embedded in carbon nanofibers. The resultant self-supporting one-dimensional molybdenum carbide@nitrogen-doped carbon nanofiber (MoC-A@NCNF), prepared with polyoxometalate anion (POM) and polyvinylpyrrolidone (PVP), exhibits excellent anti-aggregation behavior. Benefiting from its high specific surface area and one-dimensional conductive network structure, the MoC-A@NCNF displays outstanding hydrogen evolution reaction (HER) performance in both 1 M KOH and 0.5 M H2SO4, achieving overpotentials of 491 mV and 568 mV at a current density of 1 A cm−2, respectively. Furthermore, it exhibits exceptional electrochemical stability during prolonged HER testing under both acidic and alkaline conditions.

Designing Mo-based transition metal dichalcogenides for sustainable hydrogen production: Anionic substitution and DFT insight

Anionic substitution is an effective approach to optimize the catalytic activity of Mo based transition metal dichalcogenide (TMD)- MoS2 towards hydrogen evolution reaction (HER). By optimizing the S-to-Se ratio, materials with the ideal Gibbs free energy of hydrogen adsorption (ΔGH) values are synthesized (MoS2, MoS1.4Se0.6, MoS1.2Se0.8, MoSSe, MoSe2) and their HER performance is examined in 0.5 M H2SO4 solution. Density functional theory calculations of hydrogen adsorption energy on the surface of the electrocatalysts show that Se substitution facilitates electron transfer between the catalyst surface and the hydrogen donor, thereby lowering the additional potential required for water splitting, making MoS1.2Se0.8 the most favorable HER electrocatalyst with the lowest value of adsorption energy. Further enhancement in the electrocatalytic activity of mixed anion TMDs has been achieved by the incorporation of carbon nanotubes (CNTs). MoS1.2Se0.8-CNT nanocomposite exhibits superior HER performance with an overpotential of 118 mV and a Tafel slope of 63 mV/decade as compared to MoS1.2Se0.8 sample owing to the synergetic effect from CNTs and MoS1.2Se0.8.

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.