Self-assembled RuO2@IrOx core-shell nanocomposite as high efficient anode catalyst for PEM water electrolyzer

Herein, a self-assembled RuO2@IrOx core-shell heterostructure nanocomposite is designed and constructed to mediate oxygen evolution activity and sufficient durability. Enhanced by synergistic interactions of heterojunction between RuO2 and IrOx, the RuO2@IrOx nanocomposite reveals lower overpotential (215 mV at 10 mA cm−2) than RuO2 (260 mV at 10 mA cm−2) and IrO2 (316 mV at 10 mA cm−2). After assembled into a homemade single-cell PEM water electrolyzer, a lower cell voltage of 1.683 V at 1 A cm−2 for RuO2@IrOx anode is obtained, compared with RuO2 (1.715 V at 1 A cm−2) and IrO2 (1.748 V at 1 A cm−2). Additionally, the RuO2@IrOx anode shows good stability at 1 A cm−2 over a 300 h stability test due to the effective protection of IrOx shell. This work offers an effective strategy to design and construct high efficient and long-term stable catalysts simultaneously.