Enhanced photocatalytic performance of sensitized mesoporous TiO2 nanoparticles by carbon mesostructures

Abstract

In this article, sensitized TiO₂ photocatalysts were prepared by combining a hydrothermal process with a post-thermaltreatment. Results indicate that the post-thermal treatment is an effective and facile method to promote the photocatalytic activity of the sensitized TiO₂. The sensitized TiO₂ photocatalysts calcined at an optimum temperature of 400 °C exhibit an enhanced photocatalytic activity, which is mainly related to an appropriate sensitization and the dangling bonds. The dangling bonds can absorb methyl orange (MO) molecules via van der Waals' forces and prevent the recombination of the hole–electron pair by releasing unpaired electrons or capturing other electrons. The released electron is delocalized and promoted into the conduction band by thermal energy and further transferred to O₂, thus generating a superoxide radical anion (˙O²⁻) that is responsible for the degradation of MO in the dark.