Tailoring the Oxygen Vacancies and Electronic Structures of Hex-Wo3 (100) Crystal Plane with Heteroatoms Toward Highly Efficient Hydrogen Evolution

Due to the difficulty of developing noble materials for the large-scale application, transition metal oxides (TMOs) materials have become the choice of electrocatalytic hydrogen evolution reaction (HER). However, compared to commercial Pt/C, TMOs such as WO 3-x based, is unsatisfied with poor conductivity and activities similar to the semiconductors for HER performance, so it is necessary to meliorate the electrode self-properties to be suited for H 2 production. Here, Ni 0.4 WO 3-x S x was prepared by minor S atom doping and Ni atom loading strategies, that is, different ratio of S 2- cation and Ni 2+ anion salts are introduced into the hex -WO 3 NRs (hexagonal WO 3 nanorods) prepared precursors to fabricate oxygen vacancies and W-S active sites. The XPS, Raman and EIS results show that the incorporation of Ni and S atoms can increase the number of oxygen vacancies and conductivity of hydrogen evolution, at the same time, W-O-S and Ni-W-O bonds is mainly active sites of the Ni 0.4 WO 3-x S x NRs, the DFT calculation results further indicate the ΔG H* of NiWO 3-x S x is closer to Pt/C. The Tafel slope is reduced to 87.3 mV/dec approach to Volmer–Heyrovsky kinetic mechanism reaction. Finally, the one-set potential is 53 mV and the overpotential is 173mV at 10 mA/cm 2 current density, which has been reduced by 68% compared with hex -WO 3 .