3D Co3O4-RuO2 Hollow Spheres with Abundant Interfaces as Advanced Trifunctional Electrocatalyst for Water-Splitting and Flexible Zn-Air Battery

Exploiting efficient and stable electrocatalysts with trifunctional catalytic activity toward hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) act has a crucial role with sustainable energy development. Therefore, this study fabricates Co3O4-RuO2 hollow spheres using a facile and eco-friendly solvothermal and low temperature oxidation procedure followed by ice water treatment (IW-Co3O4-RuO2-HS). The specific hollow nanostructure could provide sufficient active sites and channels in the electrocatalytic procedure. Then, the IW-Co3O4-RuO2-HS presents small overpotentials toward HER (40 mV@ 10 mA cm(-2)) and OER (250 mV@ 10 mA cm(-2)), and high half-wave potential for ORR (E-1/2@ 0.79 V). Remarkably, the IW-Co3O4-RuO2-HS also presents superior catalytic performances toward water-splitting and flexible rechargeable Zn-air batteries. Furthermore, the water electrolysis can be driven by sustainable energy, including solar, wind, thermal energy, and the assembled flexible rechargeable Zn-air battery. This study provides a valid path to synthesize multifunctional electrocatalysts on energy-related devices.