Modulation in Ruthenium–Cobalt Electronic Structure for Highly Efficient Overall Water Splitting
Yunkai Bao, Jianying Dai, Jun Zhao, Yun Wu, Chuan Li, Lifei Ji, Xin Zhang, Fengchun Yang
Abstract
It is of great significance to develop high efficiency and economical electrocatalysts to realize the overall water splitting including the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) for renewable energy sources. Here, a new class of Ru1Coy nanoparticles (NPs) with a smaller size (5 nm) is designed via a hydrothermal method for overall water splitting in an alkaline medium. The Ru/Co atomic ratio of the starting Ru1Coy NPs is adjusted experimentally, revealing that the difference of electrocatalytic activity is caused by the adjustment of electronic structure and the change of active surface area. The optimized Ru1Co2 NP catalyst exhibits excellent electrocatalytic performance with a lower overpotential of 240 mV for OER and 188 mV for HER at the current density of 10 mA cm–2. Moreover, the overall water splitting performance is demonstrated; a cell voltage of only 1.59 V is needed to reach the current density of 10 mA cm–2. This work provides a direction for the design of bimetallic catalysts with high activity and stability.