▎ 摘　　要

The reduced graphene oxide/Ni foam(rGO/NF) composite substrate was prepared firstly via a facile method of reducing graphene oxide directly by Ni foam. Then the Pd/rGO/NF and CoOx/rGO/NF electrodes were synthesized by conventional methods of electrodeposition and hydrothermal synthesis. The structure, morphology and composition of the composite substrate and two electrodes were characterized using XRD, SEM, TEM, XPS and Raman analysis. The performance of the two electrodes for H2O2 electroreduction and Al-H2O2 fuel cells were both investigated. The morphology of rGO/NF composite can be adjusted by changing the concentration and pH of GO suspensions. A compact, uniform and pleated rGO coating on the Ni foam surface was obtained at the GO concentration of 2 g L-1 and pH = 7. Metallic Pd nanoparticles with a size of 7-8 nm and hybrid CoO/Co3O4 composite nanosheets were decorated on the rGO/NF composite substrates. The Pd/rGO/NF and CoOx/rGO/NF electrodes showed higher catalytic activity for H2O2 reduction than the Pd/NF and CoOx/NF electrodes. Al-H2O2 semi-fuel cells with the two electrodes as cathodes presented a maximum power density of 267 mW cm(-2) and 240 mW cm(-2) in the catholyte of 0.5 mol L-1 H2O2 + 3.0 mol L-1 NaOH at 50 degrees C, respectively. (C) 2019 Elsevier B.V. All rights reserved.