Pt–rGO–TiO2 nanocomposite by UV-photoreduction method as promising electrocatalyst for methanol oxidation

Pt/TiO2-decorated reduced graphene oxide composite as catalyst for methanol electro-oxidation with three phase junction structure has been synthesized by UV-photoreduction (denoted as p-Pt/rGO@TiO2). The obtained p-Pt/rGO@TiO2 has been detailedly characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and chronoamperometry (CA). XRD and TEM characterizations indicate that photoreduction is favorable to anchoring Pt nanoparticles (NPs) (ca. 2.2 nm) at the interface between TiO2 and reduced graphene oxide (rGO), and forming the Pt, TiO2 and rGO three phase junction structure. P-Pt/rGO@TiO2 exhibits a higher activity for methanol electro-oxidation than m-Pt/rGO and m-Pt/rGO@TiO2 (prepared by microwave-assisted polyol process). Lifetime tests demonstrate that the electrochemical durability of p-Pt/rGO@TiO2 is improved by a factor of 2 or more as compared with m-Pt/rGO and m-Pt/rGO@TiO2. XPS characterizations of p-Pt/rGO@TiO2 reveal stronger interaction between Pt and support hybrid compared with m-Pt/rGO@TiO2, which facilitates poisoning species removal and prevents Pt nanoparticles from migrating/agglomerating on or detaching from carbon support. This provides a facile and promising strategy to improve both the activity and durability of electrocatalysts for DMFCs.