Integrating ZnCo2O4 submicro/nanospheres with CoxSey nanosheets for the oxygen evolution reaction and zinc–air batteries

Abstract

Developing low cost, high-efficiency and robust electrocatalysts to boost the oxygen evolution reaction (OER) is of great significance for clean energy storage and conversion devices such as electrochemical water splitting devices, rechargeable zinc–air batteries, and so on. In this study, we present a facile means to integrate ZnCo₂O₄ submicro/nanospheres with Co_xSe_y (x and y denote the molar ratio of Co and Se, respectively) nanosheets, and such a composite exhibited excellent OER activity with an overpotential of 324 mV at 10 mA cm⁻² in 1 M KOH. It also exhibited superior long-term stability to the benchmark IrO₂ catalyst. In the home-made zinc–air battery test, the battery modified with the composite as the air cathode showed excellent performance with a small voltage gap of 0.98 V at 50 mA cm⁻², a high power density of 212.9 mW cm⁻², a high specific capacity of 570.1 mA h g⁻¹, and a stable cycling stability (50 h) at 10 mA cm⁻² with a round-trip efficiency of 56.3%, superior to the IrO₂/C counterpart. This study can provide an avenue for developing cost effective, efficient and durable OER electrocatalysts as alternatives for various renewable energy storage and conversion devices.