Amorphous titania matrix impregnated with Ag nanoparticles as a highly efficient visible- and sunlight-active photocatalyst material

Amorphous titania matrix impregnated with Ag nanoparticles has been synthesised based on a facile colloidal synthesis route and has been explored for visible- and sunlight-activated photocatalytic applications. The photocatalytic activity of the material under visible light and sunlight irradiation was demonstrated by investigations on the degradation of a common pollutant, nitrobenzene. In comparison to other TiO2-based nanomaterials, this amorphous titania impregnated with Ag nanoparticles was found to be highly efficient for visible light as well as sunlight-active photocatalytic applications. The superior catalytic activity could be attributed to the efficient charge separation and lessened recombination of the photo-generated electrons and holes at the Ag–titania interface and the presence of multiple metal–metal oxide interfaces due to dispersed impregnation of Ag nanoparticles on amorphous titania matrix. Also, it was found that the photocatalytic activity of the prepared nanocomposites had better efficiency under the sunlight irradiation, which may be attributed to the plasmonic heating of the Ag nanoparticles in the sunlight. Fundamentally, this work illustrates that the dispersed impregnation of noble metal nanoparticles on semiconductor metal oxide matrix can be used to tune the photophysical properties of the final material to enhance its photocatalytic performance.