Plasma-engineering of Pt-decorated NiCo2O4 nanowires with rich oxygen vacancies for enhanced oxygen electrocatalysis and zinc-air battery performance

The development of low-cost and efficient bifunctional catalysts is of great importance for the advancement of high-performance rechargeable zinc-air batteries. In this study, we present a composite material comprising Pt-decorated NiCo 2 O 4 nanowires enriched with abundant oxygen vacancies, designed as an excellent bifunctional electrocatalyst for both the oxygen evolution reaction and the oxygen reduction reaction. The introduction of Pt atoms and oxygen vacancies onto the NiCo 2 O 4 nanowires was achieved with the assistance of plasma treatment. This approach resulted in a catalyst with a greater number of active sites, enhanced surface conductivity and significantly improved electrocatalytic activity compared to the original NiCo 2 O 4 nanowires. Moreover, the zinc-air battery based on this composite catalyst exhibits a narrow charge/discharge voltage gap and superior stability, which is better than batteries employing commercial noble-metal-based catalysts. This work provides a rational strategy for the construction of high-active and cost-effective Pt-based electrocatalysts. Combining the excellent OER performance of spinel-type NiCo 2 O 4 nanowires with the outstanding ORR activity of Pt atoms allows the composite Pt/Ar-NCO electrocatalyst to exhibit excellent bifunctional electrocatalytic performance and stability. • A composite catalyst, Pt-decorated NiCo 2 O 4 nanowires enriched with abundant oxygen vacancies, is reported. • The introduction of Pt atoms and oxygen vacancies onto NiCo 2 O 4 nanowires was achieved with the assistance of plasma treatment. • This composite catalyst exhibits excellent bifunctional electrocatalytic performances. • This composite catalyst was used as a binder-free air cathode for the rechargeable zinc-air battery.