Atomic Ru-modulated Ru-CoO heterostructures as efficient bifunctional electrocatalyst for oxygen and hydrogen evolution reactions

Regulating morphology and composition of catalysts is of grand importance to enhance their electrocatalytic activity in energy-related fields. Herein, an electrocatalyst of ruthenium-cobalt oxide (Ru-CoO) heterojunctions decorated with atomically dispersed Ru atoms is constructed with a simple and effective salt fractionation approach. The morphology and structure of the resulting Ru-CoO were analyzed using scanning electron microscopy, transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, powder X-ray diffraction, N2 sorption, and X-ray photoelectron spectroscopy, respectively. Owing to the synergistic contributions of heterostructured Ru-CoO with abundant interfaces and single atomic Ru at doping level, the resulted Ru-CoO exhibits excellent bifunctional electrocatalytic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performances along with long-term durability under alkaline electrolytes. To attain a current density of 10 mA cm−2, the hybrid needs overpotentials of 340 and 359 mV for the OER and HER, respectively, excelling many reported catalysts to date. Importantly, this work paves a new route toward the development of efficient catalysts for the future of hydrogen economy.