▎ 摘　　要

Development of high-performance electrocatalysts in basic electrolyte is of significance for the decrease in unnecessary energy consumption for production of hydrogen. Herein, we have demonstrated one-step chemical reduction strategy to fabricate platinum-nickel alloy nanoparticle-supported reduced graphene oxide (rGO) as excellent electrocatalysts for hydrogen evolution reaction (HER) in basic condition. Graphene-supported alloy nanocatalysts are achieved by simply controlling the molar ratios of bimetallic precursors. We confirm that nickel species on the surface of as-synthesized nanocatalysts tend to be oxidized as nickel hydroxide during the fabrication. Our nanocatalysts synthesized at the equivalent molar ratios of platinum and nickel salts exhibit much higher electrocatalytic activity for HER than the commercial Pt/C and graphene-supported Pt counterparts in same conditions. The performance improvement is not only attributed to nickel hydroxide layer on our nanocatalysts facilitating the decomposition of water in basic media but also ascribed to the partial replacement of Pt atoms by Ni ones decreasing the Pt-H bond energy and improving desorption of hydrogen atoms on Pt-Ni alloy nanocatalysts. Furthermore, our nanocatalysts present excellent HER catalytic stability. Our results will provide a facile and effective strategy on the development of the excellent Pt-containing composite nanocatalysts for applications in electrocatalysis.