Photocatalytic properties of porous C-doped TiO2 and Ag/C-doped TiO2 nanomaterials by eggshell membrane templating

Porous organic carbon-doped titania (C-TiO₂) nanomaterials and their composites with Ag nanoparticles (Ag/C-TiO₂) were synthesized by an eggshell membrane templating method, and their structural and photocatalytic properties were systematically characterized. These nanomaterials, exhibiting a macroscopic morphology of a thin film, are composed of interwoven tubes, and the tube wall consists of nanocrystals. The doped organic carbon was composed of the active carbon and carbonate species, which could form a layer around the surface of TiO₂ nanoparticles, while the silver was incorporated into Ag/C-TiO₂ composites as separated Ag nanoparticles. The degradation of methylene blue under visible light irradiation was employed to evaluate the photocatalytic activity of these as-prepared TiO₂-based materials. Both C-TiO₂ and Ag/C-TiO₂ nanomaterials showed higher photocatalytic activity than pure TiO₂ material–commercial Degussa P25. These results can be accounted for the coupling effect of the incorporation of carbon species and Ag nanoparticles.