Surface engineered NiO–Co3O4 nanostructures as high-performance electrocatalysts for oxygen reduction reaction

Abstract

The development of low-cost and high-performance oxygen reduction reaction (ORR) catalysts is important for renewable energy storage and conversion systems, such as fuel cell. Herein, we report a simple and facile surface engineering strategy for nickel and cobalt based (NiO–Co3O4) hybrid as efficient and robust ORR electrocatalyst. The surface nanostructure of NiO–Co3O4 nanohybrids can be easily tuned by controlling the precursor amounts of nickel and cobalt during a wet-chemical synthesis. With an optimal composition, an intriguing surface structure consisted of one dimensional (1D) nanorod with two dimensional (2D) nanosheet can be obtained for NiO–Co3O4 nanohybrids, which significantly boosts ORR electrocatalytic activity as well as stability. A facile charge or mass transfer within 1D and 2D open surface nanostructures is mainly responsible for an excellent catalytic performance of NiO–Co3O4 nanohybrids.