Rational Engineering Co_xO_y Nanosheets via Phosphorous and Sulfur Dual-Coupling for Enhancing Water Splitting and Zn–Air Battery

Herein, an efficient multifunctional catalyst based on phosphorus and sulfur dual-doped cobalt oxide nanosheets supported by Cu@CuS nanowires is developed for water splitting and Zn–air batteries. The formation of such a unique heterostructure not only enhances the number and type of electroactive sites, but also leads to modulated electronic structure, which produces reasonable adsorption energy toward the reactant, thereby improving electrocatalytic efficiency. The catalyst demonstrates small overpotentials of 116 and 280 mA cm⁻² to achieve 10 mA cm⁻² for hydrogen and oxygen evolution, respectively. As a result, a developed electrolyzer displays a cell voltage of 1.52 V at 10 mA cm⁻² and long-term stability with a current response of 92.3% after operating for 30 h. Moreover, using such a catalyst in the fabrication of a Zn–air battery also leads to a cell voltage of 1.383 V, along with a power density of 130 mW cm⁻² at 220 mA cm⁻².