Effects of platinum on photo-assisted electrocatalytic activity of fringe-shaped highly ordered mesoporous titanium dioxide film

The platinum modified titanium dioxide film with highly ordered mesoporous framework is prepared by spin-coating method and applicated as the catalyst support material of direct methanol fuel cell, combining electro-photo catalysis innovately at different platinum (0-5 wt%) and anatase/rutile ratios. In this method, the well-ordered mesostructure with high-quality and large domain regularity are observed by field emission scanning electron microscope; meanwhile, platinum nanoparticles are homogeneous dispersed in the mesoporous framework of titanium dioxide films. As shown by the amperometric photocurrent-time curves and cyclic voltammetry, the overall photocurrent of 3 wt% platinum modified titanium dioxide film with UV irradiation is significantly 1.5 times higher than that of bare titanium dioxide film. This is further authenticated by the band gap data calculated and explained by electrochemical impedance spectroscopy measure results, which suggests that the superiority of platinum modified titanium dioxide film is attributed to the bicrystalline (anatase/rutile) framework, high crystallinity, mesoporous structure of films and the separation of photoinduced electron hole pairs.