Ruthenium-Induced Activation of Molybdenum-Cobalt Phosphide for High-Efficiency Water Splitting

Abstract

Advancing green hydrogen production technologies relies heavily on the development of highly efficient and durable bifunctional catalysts for overall water splitting. Herein, this study reports the ruthenium-modified hollow cubic molybdenum-cobalt phosphide (Ru-MoCoP) as exceptional performance electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Theoretical calculations and experimental results indicate that the incorporation of Ru not only serves as an efficient active site, but also adjusts the electronic structure and improves the reactivity of the original sites, as well as generates more phosphorus vacancies, which improves the electrical conductivity and exposes more active sites. Benefiting from the advantages triggered by the incorporation of Ru mentioned above, the Ru-MoCoP delivers low overpotentials of 55 and 240 mV at 10 mA cm⁻² for HER and OER, respectively. Furthermore, the electrolyzer assembled with Ru-MoCoP achieves a current density of 50 mA cm⁻² at 1.6 V and can be operated stably for 150 h. Notably, the assembled two-electrode system can be powered by a single commercial AA battery, accompanied with evident gas bubble evolution. This research proposes a promising strategy for the development of highly efficient bifunctional phosphide catalysts, aiming to achieve efficient energy conversion in a wide range of industrial applications.