Ternary PtVCo dendrites for the hydrogen evolution reaction, oxygen evolution reaction, overall water splitting and rechargeable Zn–air batteries

Abstract

Designing a highly active, robust and cost-effective electrocatalyst with multiple functionalities toward overall water splitting and rechargeable Zn–air battery applications is crucial and urgent for the development of sustainable energy sources. Herein, we report the one-step facile fabrication of ternary PtVCo alloyed dendrites as highly efficient bifunctional catalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), as well as their deployment for both overall water splitting and rechargeable Zn–air batteries. Their HER activity and long-term durability were superior to those of commercial Pt/C, and their OER performance was close to that of the standard IrO₂ catalyst. The PtVCo modified electrode can catalyze water splitting very efficiently. Furthermore, in the self-assembled rechargeable Zn–air battery test, PtVCo exhibited a narrow charge–discharge voltage gap of 0.88 V and a maximal power density of 235 mW cm⁻², which outperformed the performance of Pt/C. The excellent performance of PtVCo is mainly attributed to the synergistic contributions from Pt, V and Co, as the introduction of two transition metals significantly alters the electronic structure and the surface local ordering arrangements.