▎ 摘　　要

In this work, a facile method was used to synthesize the heterostructured bimetallic catalyst Pd-Ag/graphene (simplified as Pd-Ag/GNs). In order to achieve the heterostructured Pd-Ag nanoparticles (NPs), Ag2O was firstly produced on GNs from AgOH under UV irradiation, then the heterogeneous phase between the precursor Pd2+ and Ag2O contributes to the formation of the highly dispersed heterostructured Pd-Ag NPs with the average diameter of 5 nm on GNs after a synchronous reduction process. Electro-catalytic performances of Pd-Ag/GNs were investigated by cyclic voltammetry (CV), chronoamperometry, COad stripping voltammetry, and electrochemical impedance spectroscopy (EIS). It is shown that Pd-Ag/GNs has a much higher catalytic activity (595 mA mg(-1)) and stability for methanol oxidation reaction (MOR) and improved tolerance of CO compared with the counterpart Pd/GNs and the commercial 20% Pd/C catalyst (Pd/C-SA). And under visible light irradiation, the catalytic activity and stability of Pd-Ag/GNs are remarkably enhanced. Especially, its mass activity is 1128 mA mg(-1) which is 1.9 times higher than that without light irradiation. The significantly improved performance benefits from the efficient electro-photo synergistic catalysis for MOR under visible light irradiation, which is in favor of harvesting sunlight to produce clean energy.