Engineering the surface active sites of actiniae-like hierarchical Fe3O4/Co3O4 nanoheterojunction for efficient oxygen reduction reaction

Abstract

For the purpose of revealing the interplay between nanostructure, chemical composition and electrocatalytic oxygen reduction reaction (ORR) activity, actiniae-like hierarchical Fe3O4/Co3O4 nanoheterojunctions with controlled porosity and textural parameters are flexibly constructed through a solvothermal quasi-reverse-emulsion approach. The electrocatalysts possess high specific surface area (302–810 m2 g−1), optimized multipore size distribution as well as pore volume. The actiniae nanoheterojunctions exhibit excellent electrocatalytic ORR activity, outstanding long-term stability and methanol tolerance in alkaline solution. Correlation analysis demonstrates that the electrocatalytic ORR activity of a porous nanoheterojunction is not merely directly proportional to its specific surface area. It is also governed by suitable surface chemistry engineering of the electrocatalyst material. This work provides the validity and generality of our strategy to derive high ORR activity from nonprecious transitional metal oxides.