Coupling of ruthenium with hybrid metal nitrides heterostructure as bifunctional electrocatalyst for water electrolysis

Noble metal-based materials are the benchmark catalysts for electrocatalysis, but their wide applications are hindered due to their scarcity and high cost. Developing a feasible strategy to achieve higher catalytic activity with low usage of noble metals is vital and urgent. Herein, a simple nitridation route is proposed to design a hybrid material with both ruthenium (Ru) species and mixed metal nitride matrixes (Ru-NiWNx). Benefitting from the intrinsic high conductivity of metal nitrides, abundant catalytic active sites, and strong electron interactions, the Ru-NiWNx catalyst shows excellent bifunctional activity in alkaline electrolytes. The overpotentials are 70 mV and 270 mV at the geometric current density of 100 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. After further assembly into an electrolyzer, the Ru-NiWNx also shows superior performance. The voltage of the electrolyzer only needs 1.49 V to reach 100 mA cm−2 at the test temperature of 80 °C, indicating the promising application for hydrogen production. Our work paves a new strategy to design high-active hybrid materials for overall water splitting.