▎ 摘　　要

There is great interest in using carbon materials in the anode as a scaffold for nanostructural water-splitting catalysts. Here the graphene oxide membrane was used as a scaffold to grow nickel oxide/nickel heterostructures under thermal annealing at different temperatures. The formation of reduced graphene oxide (RGO)-NiO/Ni heterostructure membranes was confirmed by structural characterization and thereby used as electrocatalysts for the oxygen evolution reaction (OER) in basic solution. The OER performance was optimized with the sample annealed at 500 degrees C, with a NiO/Ni core/shell structure, where the average NiO size was similar to 6 nm. A Tafel slope of 81 mV/decade was measured for the sample, with a potential of similar to 1.76 V to achieve a current density of 10 mA/cm(2). In comparison with the three-dimensional (3D) RGO foam previously studied, the catalysts on RGO membranes show weaker OER performance, possibly due to less porous surfaces in a tightly packed layered structure, which may limit the access of electrolytes for ion transport and reaction. Our current study suggests that future work may need to focus on 3D RGO foam scaffolds for growth of efficient water-splitting nanocatalysts. (C) The Author(s) 2017. Published by ECS.