Construction of core–shell Co-NC@W2N Schottky heterojunctions for high-efficiency hydrogen evolution reaction

[Display omitted] •W2N was sputter-coated on metal–organic framework microarrays.•Co-NC@W2N Schottky heterojunctions facilitate charge transfer between Co-NC and W2N.•Co-NC@W2N had superior HER performance at high current densities vs Pt catalysts. Tungsten-based nitrides are ideal hydrogen evolution reaction (HER) electrocatalysts owing to their Pt-like electronic structures, high electrical conductivity, and good corrosion resistance. However, the conventional preparation of tungsten-based nitride electrocatalysts suffers from environmentally hazardous sources and high-temperature nitridation processes, which usually restrict HER activity. Herein, we report the direct synthesis of W2N on metal–organic framework (MOF)-derived Co-NC microarrays using magnetron sputtering. Co-NC microarray support increased the number of surface activity sites that were exposed to W2N. Moreover, the formation of Co-NC@W2N Schottky heterojunctions significantly facilitated charge transfer between Co-NC and W2N. The Co-NC@W2N heterojunctions showed outstanding HER activity with an overpotential of 55 mV in reaching a current density of 10 mA cm−2. Notably, Co-NC@W2N exhibited superior HER performance to Pt/C catalyst at high current densities. This study provides a simple and environmentally friendly approach for fabricating high-performance metal-nitride catalysts for water splitting.