Facile and large-scale preparation of N doped TiO2 photocatalyst with high visible light photocatalytic activity

Abstract

High visible light photocatalytic activity of N-doped TiO2 (N-TiO2) photocatalysts were prepared by facile sol-gel method in large-scale without separation, purification and thermal treatment at high temperature. Ammonium nitrate (AN) was used as nitrogen source and solid substrates, hydrous TiO2 deposited onto the surface of AN micro-particles during the formation of compound gel. AN thermal decomposed and N-TiO2 photocatalysts were obtained by compound dry gel (CDG) calcined at low temperature. N element thermal diffused enter into lattice of TiO2, and the effects of AN evidently facilitated the product transformation from amorphous to anatase. Meanwhile, the doped N element promoted the formation of doping level and its light absorption edge extended to visible region. We systematically research the doping ratio of AN, the different calcined time at low temperature to prepare N-TiO2 with high photocatalytic activity in visible region. As-prepared N-TiO2 photocatalysts exhibited excellent photocatalytic activity under the illumination of visible light, and the photodegradation reaction rate constant was approximately 6 times higher than pure TiO2 samples.