Amines for feasible synthesis of mesoporous nitrogen-doped titania anatase for visible light photocatalysis

Nitrogen doping is an efficient avenue for creating visible light-driven titania-based semiconductor materials. In this study, mesoporous nitrogen-doped titania (meso-TON) anatase phase photocatalysts were successfully prepared by sol-gel or solvent evaporation induced self-assembly methods. Dodecylamine and diethylenetriamine were used as surfactants for endowing mesoporosity, complexing agents, base catalysts, and sources for nitrogen doping. The preparation method, the titania source, and the amount of dodecylamine and diethylenetriamine strongly influenced the textural [specific surface area, pore volume, and average pore diameter] and optical [UV-Vis absorbance, band gap energy, and photoluminescence emission] properties, and photocatalytic performance. XPS study revealed the presence of substitutional and interstitial oxidized nitrogen doping. All meso-TON photocatalysts, because of reducing exciton recombination rate, showed superiority in degrading methylene blue dye compared to the available Fluka titania anatase under visible irradiation (400-800 nm). The best meso-TON photocatalyst with the highest surface area, pore volume, surface nitrogen concentration, and smallest band gap displayed the fastest rate for photodegradation and very good recyclability for five times. Holes were responsible for the photodegradation on the valence band. The novelty lies in an acid-free dual-amine route where DDA and DETA create a cooperative templating, catalytic, and doping effect for improved performance.