Tuning the Electronic Structure of Tungsten Oxide for Enhanced Hydrogen Evolution Reaction in Alkaline Electrolyte

Abstract Engineering the electronic structure of HER catalysts has been suggested to improve the performance of noble metal‐free catalysts in alkaline electrolytes. Herein, we demonstrated that a suitable cation doping in the tungsten oxide catalyst modified the interfacial structure, surface chemical state and band gap value, which enhanced the HER performance. For the experiments, the cation (Ni, Co and Fe) doped tungsten oxide catalysts were synthesized on nickel foam, on which Ni‐based alloy was decorated. The Co doped catalyst (Co−WO) exhibited an extraordinary HER activity, with a low overpotential of 30 mV at a current density of 10 mA cm −2 , Tafel slope of 32 mV dec −1 . In this system, the Ni‐based alloy–tungsten oxide interface facilitated water dissociation. Moreover, the decreased band gap and improved conductivity induced by Co doping, further enhanced the charge transfer ability in the HER process. The regulated metal‐oxide heterostructure coupled with cation doping endowed the catalyst with efficient interface active sites, superior electrical conductivity, and enhanced electron transfer kinetics, facilitating the HER performance.