Synthesis and characterization of F-N-W-codoped TiO2 photocatalyst with enhanced visible light response

Anatase F-N-W-codoped TiO2 photocatalyst was successfully prepared by a method combining sol–gel with hydrothermal treatment. Effects of F, N and W ion dosage concentration on the crystallinity, morphology, grain size and chemical status of the photocatalyst were investigated. The results showed that the F-7NW-TiO2 photocatalyst composed of uniform ellipsoidal particles around 20 nm in length and 10 nm in width, and the photocatalyst displayed enhanced visible-light absorption and photocatalytic activities. Using the photocatalyst and under visible irradiation for 1.5 h, the decoloration percent of RB and carbon removal rate were about 98% and 94% respectively, which were much higher than that of commercial P25, TiO2, N-W-TiO2 and F-TiO2. The high visible-light photocatalytic activity of F-7NW-TiO2 might result from narrowing the band gap and lowing charge pairs recombination rate for the WxTi1−xO2, OTiN and valence variation of W ions existing.