Activating Nickel-tungsten alloy for efficient alkaline hydrogen evolution via interface engineering

Fe-B alloy coupled with Fe clusters as an efficient cocatalyst for photocatalytic hydrogen evolution

Boosting the HER electrocatalytic activity over RuCu-supported carbon nanosheets as efficient pH-independent catalysts

Quasi-atomic-scale platinum anchored on porous titanium nitride nanorod arrays for highly efficient hydrogen evolution

Fabrication of Pt nanoparticles on nitrogen-doped carbon/Ni nanofibers for improved hydrogen evolution activity

In the present study, we synthesized three non-heme FeIII complexes (FeIII[L1]2)- (1), (FeIII[L2]2)- (2), and (FeIII[L3]2)- (3) with 4-hydroxy pyridine-2,6-dicarboxamide (H2L1), pyridine-2,6-dicarboxamide (H2L2), and 4-methoxy pyridine-2,6-dicarboxamide (H2L3) based ligands and characterized by elemental analysis, single crystal X-ray diffraction (for 1 and 2), EPR, Möβbauer (for 1), UV-visible and infrared spectroscopy. Hydrogen evolution reaction (HER) catalytic activity of 1, 2, and 3 was performed in the presence of acids such as acetic acid (AcOH) and triethylammonium chloride/triethylammonium tetrafluoroborate (HNEt3Cl/HNEt3BF4) in dimethylformamide (DMF). In these compounds, the primary coordination sphere of Fe remained similar, forming bis-chelated hexa-coordinated complexes. However, single-crystal X-ray structures revealed that the Fe-Npyridine bond distances are different in 1 and 2. Noteworthily, complex 1 showed better electrocatalytic activity for HER with a kcat of 1.4±0.07 × 105M-1s-1 in the presence of HNEt3Cl, highlighting the significant effect of internal hydroxy functional groups in HER. The presence of additional hydroxy groups in complex 1 plays the role of a local proton source and facilitates an intramolecular proton transfer, which enhances the catalytic rates for HER. The current study emphasizes how tuning the ligand scaffolds in FeIII complexes could potentially affect their catalytic activity for HER.

Cobalt@nitrogen-doped bamboo-structured carbon nanotube to boost photocatalytic hydrogen evolution on carbon nitride

Asymmetrical radial strain energy strategy of M–N–SWCNT single atom catalysts for highly efficient hydrogen evolution: A high-throughput DFT study

Objectives It would be essential for solving the global warming problem to use renewable energy as well as increase the efficiency of energy production. One of the renewable and efficient energy sources is hydrogen energy, and the electrochemical hydrogen evolution reaction (HER) is the most important reaction in the hydrogen energy production. For HER, inexpensive catalyst development is indispensible because the precious metal Pt is being used as the most efficient catalyst for HER. Methods Density functional theory (DFT) calculations were performed using the Vienna ab initio simulation package (VASP) to calculate atomic and electronic structures and total energies using the projector-augmented wave (PAW) method. Results and Discussion The HER efficiencies of Pt(111), Pt nanoclusters, and Pt-based core-shell nanoclusters were examined based on the hydrogen adsorption energies (Eads) by using the density functional theory (DFT) calculations. The DFT results demonstrate that Pt nanoclusters (0.5 ~ 2.1 nm in diameter) showed stronger hydrogen adsorption (Eads = -0.65 ~ -1.25 eV) than that of Pt(111) (Eads = -0.61 eV), implying a lower HER efficiency of Pt nanoclusters than Pt(111). On the other hand, a Rucore-Ptshell nanocluster (Eads = -0.48 eV) showed weaker hydrogen adsorption than Pt(111), indicating an increase in the HER efficiency. The weaker hydrogen adsorption on Rucore-Ptshell was attributed to the d;-band shift of Pt atoms further away from the Fermi level in negative direction due to the core Ru atoms. Conclusion By evaluating the HER efficiency using a descriptor of the hydrogen atom adsorption strength, a Ru-Pt core-shell (Rucore-Ptshell) nanocluster was expected to exhibit the highest HER efficiency among Pt(111), Pt55 nanocluster, and Mcore-Ptshell (M = Ni, Co, Mn, Cu, Ru, Ir and Au) nanoclusters. Key words: Hydrogen Evolution Reaction (HER), Platinum (Pt) Catalysts, Nanocluster, Core-shell, Density Functional Theory (DFT), d-Band Center Theory

Development of nonprecious metal-based electrocatalysts supporting hydrogen evolution reaction (HER) in the entire pH range has gained significant importance for harvesting green and renewable energy. Herein, we developed a novel electrocatalyst based on 3D carbon nanoarchitecture hybrid, which consists of CoP nanoparticles (CoP NPs) embedded into N-doped carbon nanotubes (NCNT), grafted on carbon polyhedron (CoP/NCNT-CP) that was prepared by carbonization and low-temperature phosphatization treatment of cobalt-based zeolite imidazole framework (ZIF). Benefiting from the strong synergistic effect and unique 3D structure, the CoP/NCNT-CP hybrid loaded on Ni foam exhibited excellent electrocatalytic HER performance in base with a low overpotential of 165 mV at a current density of 10 mA cm-2, which is competitive with the previously reported Co-based hybrid electrocatalysts. Furthermore, the CoP/NCNT-CP also demonstrated high HER electrocatalytic activities in both neutral and acidic conditions with the overpotentials of 203 and 305 mV at the current density of 10 mA cm-2. Additionally, the bifunctional CoP/NCNT-CP electrode simultaneously acted as an anode for hydrazine oxidation reaction (HzOR) and a cathode for HER. Excellent catalytic performance was demonstrated in base conditions with a low cell potential of 0.89 V at 10 mA cm-2, which was much lower than the voltage of overall water splitting (1.91 V) at the same current density.

Microwave-pulse sugar-blowing assisted synthesis of 2D transition metal carbides for sustainable hydrogen evolution

For more energy-efficient and economical hydrogen production, highly active noble metal-free hydrogen evolution catalysts are a priority for all. Herein we report a facile hydrothermal synthesis of composite MoSe2-MoO2. The surface morphology and chemical composition of the synthesized materials were investigated by SEM, TEM, Raman spectroscopy, XPS and XRD. After characterizations, the materials were directly used as an electrode to evaluate their HER performance. A comparison between pure MoSe2, pure MoO2 and MoSe2-MoO2 nanosphere shows that the porous MoSe2-MoO2 nanosphere exhibits higher catalytic activity for electrocatalytic hydrogen evolution reaction (HER)(figure 1). Based on our data, it can be concluded that the porous structure material could improve the surface active area which yields higher HER catalytic activity. The present study provides a simple and effective way for the exploration of efficient Mo-based HER catalysts. Figure 1

Hydrogen evolution reaction efficiency of carbon nanohorn incorporating molybdenum sulfide and polydopamine/palladium nanoparticles

Tungsten disulfide (WS2) is well known to have great potential as an electrocatalyst, but the practical application is hampered by its intrinsic inert plane and semiconductor properties. In this work, owing to a Co-based zeolite imidazole framework (ZIF-67) that effectively inhibited WS2 growth, few-layered WS2 was confined to the surface of Co, N-doped carbon polyhedron (WS2@Co9S8), with more marginal active sites and higher conductivity, which promoted efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). For the first time, WS2@Co9S8 was prepared by mixing in one pot of a liquid phase and calcination, and WS2 realized uniform distribution on the polyhedron surface by electrostatic adsorption in the liquid phase. The obtained hybrid catalyst exhibited excellent OER and HER catalytic activity, and the OER potential was only 15 mV at 10 mA cm-2 higher than that of noble metal oxide (RuO2). The improvement of catalytic activity can be attributed to the enhanced exposure of sulfur edge sites by WS2, the unique synergistic effect between WS2 and Co9S8 on the metal-organic framework (MOF) surface, and the effective shortening of the diffusion path by the hollow multi-channel structure. Therefore, the robust catalyst (WS2@Co9S8) prepared by a simple and efficient synthesis method in this work will serve as a highly promising bifunctional catalyst for OER and HER.

Recently, molybdenum dioxide (MoO2) has gained intensive attention as an eco‐friendly and earth abundant catalyst for electrocatalytic hydrogen evolution from water splitting. However, the catalytic activity of MoO2 catalyst for hydrogen evolution reaction (HER) is severely limited by the less exposed active sites. Herein, we present Co‐doped MoO2 for efficient HER through a facile wet chemistry synthesis followed by calcination treatment process. The optimized Co‐MoO2‐0.01 nanorods (NRs) delivers a very low overpotential of 26 mV at 10 mA cm−2 and a small Tafel slope of 30.9 mV dec−1, which is much better than that of pure MoO2 NRs and the commercial Pt/C catalyst in HER. Experimental and theoretical results reveal that Co doping not only produce more oxygen vacancies in MoO2, which can activate adjacent oxygen atoms as active sites and thus increase the exposed active sites on the surface of catalyst, but also enhance the electrical conductivity of catalyst during HER process. In a word, this work provides a new promising synthetic strategy for developing earth‐abundant and cost‐effective HER electrocatalysts through rational defect‐engineering design.

The hydrogen evolution effect has been widely demonstrated to enhance the kinetics of the hydrogen evolution reaction (HER) by decoupling the water splitting and hydrogen recombination steps. Although interlayer water has been shown to promote proton transport in transition metal oxides and enhance the hydrogen evolution effect, the intrinsic mechanism underlying HER catalysis based on this process remains unclear. In this study, we systematically investigated the role of structural water in regulating the HER catalyzed by WO3 through first-principles calculations. By constructing a series of layered WO3 models with controllable hydration levels (WO3, WO3⋅0.5H2O, and WO3⋅H2O), we found that water intercalation significantly reduces the hydrogen adsorption energy, from −2.513 eV in the anhydrous state to −0.609 eV in the fully hydrated state, thereby optimizing hydrogen bonding strength to achieve an efficient HER. Electronic structure analysis indicates that water molecule intercalation alters the coordination environment of lattice oxygen, leading to a reduction in the density of states near the Fermi level. Crucially, the combined results of density functional theory and ab initio molecular dynamics calculations indicate that the interlayer insertion of water simultaneously increases the water splitting energy barrier. These findings suggest that the design of WO3-based HER catalysts should fully leverage the advantages of interlayer water in promoting proton transport and optimizing hydrogen adsorption, while the selection of synergistic materials should avoid reliance on the reverse hydrogen overflow mechanism, providing a clear design direction for the development of efficient WO3-based HER catalysts.