SYNTHESIS AND CHARACTERIZATION OF PALLADIUM NANOPARTICLES IMMOBILIZED ON TiO_2 NANOTUBES AS A NEW HIGH ACTIVE ELECTRODE FOR METHANOL ELECTRO-OXIDATION

摘要

Self-organized TiO_2 nanotubes/titanium substrate modified with palladium nanoparticles (Pd/TiO_2/Ti electrodes) were prepared by a two-step process consisting of anodizing of titanium plate followed by electroless plating of palladium on resulted TiO_2 nanotubes. The morphology and surface analysis of Pd/TiO_2/Ti electrodes were investigated using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. The results indicated that palladium nanoparticles were homogeneously deposited on the surface of TiO_2 nanotubes. The electro-catalytic activity of Pd/TiO_2/Ti electrodes in the methanol electrooxidation was studied by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) methods. The results indicate that Pd/TiO_2/Ti electrode improve the electro-catalytic activity for methanol oxidation greatly and confirmed the better electro-catalytic activity and stability of these new electrodes. So, the Pd/TiO_2/Ti electrodes have a good application potential to fuel cells.