Preparation of Functionalized Graphene Multilayer Composite Films Supported Pt Catalyst and its Electro-Oxidation for Methanol

Abstract

The multilayer composite films consisting of poly (diallyldimethylammonium chloride) functionalized graphene (PDDA-rGO) and phosphomolybdic acid functionalized graphene (PMo12-rGO) were prepared by layer-by-layer self-assembly method. The {PDDA-rGO/PMo12-rGO}n multilayer composite films were used as a support for electro-deposition of Pt particles in situ. Cyclic voltammetry (CV), X-ray photoelectron spectroscopy and scanning electron microscopy were employed for examining the composition, structure, and morphology of the catalyst. Results revealed that the Pt/{PDDA-rGO/PMo12-rGO}n catalyst is successfully prepared and that the multilayer composite films support improves the dispersion of the Pt particles. CV and chronoamperometry were employed to evaluate the electrocatalytic performance for methanol oxidation. Results revealed that the electrocatalytic activity and stability of the Pt/{PDDA-rGO/PMo12-rGO}3 catalyst for methanol oxidation are considerably improved in comparison with that of the Pt/GCE catalyst. The current density for the oxidation of methanol increased from 0.66 mA/cm2 to 1.21 mA/cm2. In addition, the ratio of the forward current density to the backward current density (If/Ib) was 1.92 for Pt/{PDDA-rGO/PMo12-rGO}3 catalyst, corresponding to 1.3 times that of the Pt/GCE catalyst. This result indicated that the multilayer composite films remarkably enhanced the electrocatalytic activity regarding methanol oxidation.