Facile synthesis of nitrogen-doped titanium dioxide with enhanced photocatalytic properties

TiO₂ precursor was synthesized by sol-solvothermal method with tetrabutyl titanate as the titanium source. Then the nitrogen doping was conducted on using hydrazine hydrate as the nitrogen source by hydrothermal method. Compared with P25, the obtained TiO₂ and N-doping TiO₂ both exhibited excellent photocatalytic performance in degrading methyl orange dye, which were 1.85 and 1.86 times that of P25. The higher photocatalytic efficiencies of TiO₂ and N-doped TiO₂ are related to their smaller particle sizes (14.5 and 10 nm) and abundant pore structure. Furthermore, XPS results have demonstrate the substitutionary and interdoping of nitrogen in TiO₂ lattice. Accordingly, nitrogen doping did not only maintain the crystal structure of anatase TiO₂ along with changing the band gaps, but also induced the occurrence of oxygen vacancies and Ti³⁺ to reduce the recombination rate of electron-hole pairs. Therefore, N-doped TiO₂ displayed the highest degradation rate of 99.7%. (paper)