Enhanced hydrogen evolution ability of Ru with regulation of interface electronic structure by WC/W2C heterostructure via ultrafast flash joule heating synthesis

Regulation of the electronic structure for ruthenium (Ru) based catalysts is critical but challenging to achieve highly active and stable performance at ampere-level current density for proton exchange membrane water electrolysis (PEMWE). In this work, two phase tungsten carbide heterostructure interface (WC/W₂C) is constructed to optimize adsorption of hydrogen intermediates (H*) on Ru-based heterostructure catalyst by one-step ultrafast flash joule heating. Experimental and theoretical studies indicate the obvious charge accumulation and migration at the interface region between Ru and WC/W₂C heterostructure. The H* adsorption and desorption balanced by tuning the interface electronic structure contributes synergistic effect to the HER activity of Ru-W_xC/CC. Accordingly, with a trace amount of Ru, the as-synthesized Ru-W_xC/CC exhibits an overpotential of 31 mV at 10 mA cm⁻² and 288 mV at 1 A cm⁻². Furthermore, the catalyst delivers exceptional stability during at least 500 h of operation at 10 mA cm⁻² with negligible degradation for overall water splitting. This work will provide a guidance for regulating interfacial electronic structure of hydrogen evolution catalyst by the design of heterostructure.