▎ 摘 要
The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are of great importance for energy conversion processes, such as water electrolysis, metal-air batteries, and fuel cells. Herein, we report a substrate-assisted in situ reduction method to prepare three-dimensional reduced graphene oxide (3DRGO) networks decorated with a range of mixed cobalt oxide and nickel oxide nanosheets as a new type of bifunctional catalyst for oxygen evolution and oxygen reduction. Among the different composite catalysts, Co3O4@3DRGO showed highest catalytic activities in OER and ORR with an excellent stability. This catalyst is used to catalyze the oxygen reactions in a Zn-air battery as a proof-of-concept. The current results render new insights into developing low-cost, next-generation bifunctional catalysts for photoelectrochemical cells for energy storage and conversion.