In-situ synthesis of Co3O4 nanocrystal clusters on graphene as high-performance oxygen reduction reaction electrocatalysts

Abstract

ABSTRACT The energy problem is closely related to the survival and development of human beings. Nowadays, the research of fuel cells is making rapid progress, but the bottleneck of the development of fuel cells is slow oxygen reduction reaction (ORR) of cathode. At present, it is difficult to develop a kind of oxygen reduction catalyst with high performance, low energy consumption and low pollution. Here, we synthesised Co3O4 nanocrystals loaded on a single graphene oxide layer via a convenient one-step hydrothermal method. According to the transmission electron microscopy characterisation tests, the average size of Co3O4 nanocrystals is 5 nm. Compared with the commercially available Pt/C catalyst, the obtained Co3O4/rGO catalyst demonstrates the same four-electron (4e−) oxygen reduction reaction, and the catalytic activity of ORR is significantly higher. This is due to the large surface area provided by the middle part of the composite catalyst Co3O4/rGO, which provides an effective mass transfer and electron transfer path for the catalyst.