Photo-catalytic activity of carbon/nitrogen doped TiO2-SiO2 under UV and visible light irradiation

Abstract

The sol gel synthesis method was used to prepare carbon and nitrogen doped titanium dioxide (TiO2) photo-catalyst using titanium tetrachloride (TiCl4) as the precursor. Doping was carried out to modify the absorption band edge of titanium dioxide. To avert the problem associated with use of powder TiO2, the photo-catalyst was immobilized on glass support using tetraethyl orthosilicate (TEOS), which served as a binder and precursor for silicon dioxide (SiO2). The prepared photo-catalytic materials were characterized by FT-IR, XRD, TEM, BET and DRS. The photo-catalytic efficiency of titanium dioxide immobilized on glass support was evaluated using the degradation of methyl orange (MeO) and phenol red (PRed) under ultraviolet and visible light irradiation. Doping with carbon and nitrogen, and incorporation of silicon dioxide into the titanium dioxide matrix allowed utilization of visible light by the prepared TiO2-SiO2 nano-composites. Photo-degradation tests were carried out for doped and undoped photo-catalyst. An increased rate of photo-oxidation of methyl orange and phenol red was observed under visible light irradiation as compared to UV light irradiation.