Self-standing hollow porous Co/a-WO_x nanowire with maximum Mott–Schottky effect for boosting alkaline hydrogen evolution reaction

The sufficient utilization of Mott–Schottky effect for boosting alkaline hydrogen evolution reaction (HER) depends upon scale minimizing of interface components and exposure maximizing of Mott–Schottky interface. Here, a self-standing porous tubular Mott–Schottky electrocatalyst is constructed by a self-template etching strategy, where amorphous WO_x (a-WO_x) nano-matrix connects Co nanoparticles. This novel “Janus” electrocatalyst maximizes the Mott–Schottky effect by not only providing a highly exposed micro interface, but also simultaneously accelerating the water dissociation and optimizing the hydrogen desorption process. Experimental findings and theoretical calculations reveal that Co/a-WO_x Mott–Schottky heterointerface triggers the electron redistribution and a build-in electric field, which can not only optimize the adsorption energy of the reaction intermediates, but also facilitate the charge transfer. Thus, Co/a-WO_x requires an overpotential of only 36.3 mV at 10 mA·cm⁻² and shows a small Tafel slope of 53.9 mV·dec⁻¹ as well as an excellent 200-h long-term stability. This work provides a novel design strategy for maximizing the Mott–Schottky effect on promoting alkaline HER.