The synergistic effect of graphene and polyoxometalates enhanced electrocatalytic activities of Pt-{PEI-GNs/[PMo12O40]3-}n composite films regarding methanol oxidation

The {PEI-GNs/PMo12}(n) composite films are prepared by an LBL electrostatic assembly technique, and their uniform and homogeneous traits have been verified by UV-vis and cyclic voltammetry. The {PEI-GNs/PMo12}(n) composite films are used as a novel catalyst support for electro-deposition of Pt particles in situ. Pt particles immobilizing on the surface of {PEI-GNs/PMo12}(n) composite films were confirmed by XPS, EDX, XRD and FE-SEM. The interesting seashell-like Pt micro-nano-clusters can be obtained when {2PEI-GNs/PMo12} composite films are used as catalyst supports. Pt-{PEI-GNs/PMo12}(n) composite films present good electrocatalytic activity regarding methanol oxidation and improved tolerance of CO. These results indicate that poly(ethyleneimine) functionalized graphene (PEI-GNs) preserves the superior electric conductivities of graphene sheets in the composite films, and the introduction of electroactive [PMo12O40](3-) (PMo12) into the composite films helps to convert intermediate species CO into CO2 from the Pt nanoparticles. The synergistic effect of PEI-GNs and PMo12 remarkably enhanced the electrocatalytic activity and stability regarding methanol oxidation.