Enhancing the Hydrogen Evolution Performance of WC via Microstructure Engineering

Tungsten carbide (WC) is considered an ideal electrode material for hydrogen evolution reactions (HER) due to its platinum-like d-band density of states (DOS) at the Fermi level. However, achieving high performance for HER always requires modifying WC by doping or compositing, which results in a complicated process and complex samples. This study proposes constructing microstructures in WC via a one-step high pressure and high temperature (HPHT) method to modify the HER activity. The locally distorted lattice is captured in WC under 1 GPa and 600 °C (WC-1-600), which delivers optimal HER performance of 106 mV and 125 mV at 10 mA cm-2 in acidic and alkaline electrolytes, respectively. It is only about 44.2% and 69.8% of pure WC (WC-initial) in acidic and alkaline electrolytes, respectively. It can operate stably for more than 70 and 100 h under acidic and alkaline electrolytes. The excellent HER performance of WC-1-600 is attributed to that the distorted lattice rearranging the surface electron distribution, reducing the adsorption ability of H atoms, and promoting the reaction dynamics of HER. The findings offer a new insight into optimizing catalyst performance by microstructure engineering through HPHT technology applications in electrocatalysis research.