Surfactant-assisted synthesis of NiCo alloy with specific nanopore architecture as a bifunctional electrocatalyst for rechargeable zinc-air batteries

Abstract

Designing the effective active sites and reaction areas of catalytic materials is important for the development of bifunctional electrocatalysts for zinc-air batteries (ZABs). In this paper, a catalyst with a uniform nanopore structure (noted as NiCo-PS) was one-pot synthesized by using transition metals nickel and cobalt as catalytic active components, sucrose as a carbon source, and triblock copolymers as a soft template. The N2 absorption and desorption isotherms curves show that the pore size distribution of NiCo-PS modified by surfactant is mainly in 3.6 nm range. NiCo-PS exhibits exceptional bifunctional electrocatalysis due to its effective triple-phase reaction interface from its mesoporous structure, with a positive half-wave potential of 0.758 V for ORR and a low overpotential of 390 mV at 10 mA ⋅ [Formula: see text] for OER. Furthermore, the rechargeable ZABs with the NiCo-PS catalyst exhibit a high open-circuit voltage of 1.31 V, a significant peak power density of 105 mA ⋅ [Formula: see text] at 0.56 V, and good stability throughout 270 h testing. This result offers valuable insights for designing catalysts that enhance the active region of the reaction within the cathodes of ZABs and hold significant promise for practical applications.