Design And Synthesis Of Pt/Functionalized Graphene Composites And Their Electrocatalytic Performances Toward Methanol Oxidation

In this work, two-dimensional (2D) graphene nanosheets (GNs) were functionalized with soluble macromolecule possessing some unique structures and used as scaffold materials to construct functional Pt nanostructures with designed shapes and sizes, aiming at enhancing the efficient Pt utilization. Meanwhile, some functional components such as electroactive POMs and current-illumination characteristic TiO2were also introduced into Pt/graphene composites and used to construct the defined structure of multicomponent catalysts, in order to achieve stronger synergistic interaction between different components and enhance remarkably electrocatalytic performances toward methanol oxidation.Six different type of composites in this work were designed and prepared successfully, which are listed as following:Pt/{PDDA-GNs/PSS-GNs}n multilayer composite films, Pt/{PEI-GNs/PMo12}n multilayer composite films, Pt/CS/PW]2-GNs composites, Pt/GNs-CD composites, Pt/G4/GNs-H composites&Pt/CS/GNs-H composites, and Pt/TiO2/GNs-M composites. TEM, SEM, AFM, EDX, XPS, XRD, FT-IR, UV-vis, TGA, ICP, and Raman spectra were utilized to characterize the components, constructions and morphologies of as-prepared composites. Especially, the morphologies&dispersion, formation mechanism&influencing factors of different Pt nano particles/clusters were discussed in detail, and the construction relations among different components were also discovered and optimized. Cyclic voltammetry (CV), chronoamperometry, COad stripping voltammetry, and electrochemical impedance spectroscopy (EIS) was used to study the electrocatalytic properties toward methanol oxidation. The effect of Pt nano particles/clusters morphologies&dispersion on electrocatalysis performances was discussed. And the role of different functional components (POMs and TiO2), the performances promotion originating from the well organized composite constructions, and the catalytic reaction mechanism were also investigated. As a whole, the practicabilities and catalytic performances of as-prepared composites are improved and the strategies for preparation are simpler and greener, with the deepening of our research. It should be noted that the as-prepared composites exhibit remarkably enhanced catalytic performances, compared with Pt/C catalyst (Johnson Matthey) and recently reported Pt graphene-based catalysts. Most interestingly, the mass activities for Pt/G4/GNs-H, Pt/CS/GNs-H, and Pt/TiO2/GNs-M are beyond1000mA mg-1...