Three-dimensional flower-like N-doped tungsten carbide for enhanced hydrogen evolution reaction

It has been critical and challenging to develop non-precious transition-metal-based eletrocatalysts with low-cost and long-term durability for efficient water splitting. Herein, self-supported nitrogen-doped tungsten carbide on iron-nickel foam (N-WC@INF) with three-dimensional flower-like structure was prepared by a simple hydrothermal reaction followed by simultaneous nitridation and carbonization. The resulting N-WC@INF exhibits an overpotential of 103 mV at a current density of 10 mA cm-2 in alkaline media and a low Tafel slope of 47 mV dec- 1, accompanied by a negligible loss of overpotential after 30 h consecutive hydrogen evolution reaction (HER). Additionally, N-WC@INF shows promising activity for oxygen evolution reaction (OER) with an overpotential of 224 mV at 10 mA cm-2 and a low Tafel slope of 22 mV dec- 1.