Facile low temperature immobilization of N-doped TiO2 prepared by sol–gel method

Abstract

In this study, simplified and low temperature sol–gel preparation method was investigated at different concentrations of tetraethylorthosilicate for better adhesive strength to glass support and photocatalytic decolorization activities on methylene blue. The physical and chemical characteristics of pure N-doped TiO2 and property changes due to addition of tetraethylorthosilicate were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, nitrogen adsorption–desorption isotherms, UV–Vis spectra, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and high-resolution transmission electron microscopy. The results showed that the addition of tetraethylorthosilicate significantly improved the Brunauer–Emmett–Teller surface area, the amount of hydroxyl groups and adhesive strength of the catalyst. However, the photoactivity of the catalyst was suppressed at the higher concentrations of tetraethylorthosilicate (20 and 30%). Based on these results, 5% tetraethylorthosilicate was found to be an optimum value for successful immobilization of N-doped TiO2 on the glass beads. Only 6% loss in its photoactivity was observed at the 5th cycle test indicating that deterioration of catalytic activity was very low.