Rational construction of Au@Co₂N_0.67 nanodots-interspersed 3D interconnected N-graphene hollow sphere network for efficient water splitting and Zn-air battery

To meet the demands of the future green energy industry, there is a need for the cost-effective development of high-efficient electrocatalysts with optimal durability for water splitting and Zn-air batteries. In this work, a novel multifunctional electrocatalyst based on ultrafine Au@Co₂N_0.67 core/shell nanodots interspersed 3D-NGr (Au@Co₂N_0.67/3D-NGr) with extraordinary activity and durability toward the hydrogen evolution reaction, oxygen evolution reaction, and oxygen reduction reaction has been developed that tends to show similar activity to the benchmark Pt/C and RuO₂/C catalysts. Significantly, the Au@Co₂N_0.67/3D-NGr hybrid shows excellent overall water splitting potential while requiring small cell voltages of 1.58 and 1.79 V to achieve 10 and 50 mA cm⁻², respectively. In addition, Zn-air batteries using the developed Au@Co₂N_0.67/3D-NGr hybrid demonstrate high performance, an expected open circuit potential of 1.46 V, a large power density of 142.8 mW cm⁻², good rechargeability, and a high cycling life.