Tuning electronic configuration of WP2 nanosheet arrays via nickel doping for high-efficiency hydrogen evolution reaction

Abstract Modulate the electronic structure and surface energy by nanostructure and heteroatom doping is an efficient strategy to improve electrocatalytic activity of hydrogen evolution reaction (HER). Herein, nickel incorporated WP2 self-supporting nanosheet arrays cathode was synthesized on carbon cloth (Ni-WP2 NS/CC) by in-situ phosphating reduction of the Ni-doped WO3. It shows that heteroatom doping and the three-dimensional (3D) nanosheet arrays morphology both facilitate to reduce the interfacial transfer resistance and increase electrochemical-active surface areas, which effectively improve electrocatalytic hydrogen evolution reaction (HER) activity. The optimized catalyst, 1% Ni-WP2 NS/CC, exhibits an outstanding electrocatalytic performance with an overpotential of 110 mV at 10 mA cm−2 and a Tafel slope of 65 mV dec−1 in the acid solution. DFT calculations further demonstrate the nickel doping can adjust the intrinsic structure of electronics, lower the Gibbs free energy of adsorption of hydrogen (ΔGH*), and effectively improve the HER performance.