文摘
F-N-W-codoped TiO2 nanoparticles were successfully prepared by a sol-gel-mixing method without hydrothermal or calcining treatment. Effects of the F, N and W ion dosage concentration on crystallinity, morphology, grain size and chemical status of TiO2 were investigated. The results showed that the appearance of F-N-W-codoped TiO2 powders was uniformly spheroidal nanoparticles, whose average particle size was about 7?nm. The F-N-W-codoped TiO2 nanoparticles owned high catalytic activity under visible light irradiation and low-temperature thermo-oxidation activity in the dark. The highest degradation rate of Rhodamine B dye was obtained by TiO2 powders modified with 0.5?at. % W (N/W?=?6/7) and 4.0?at. % F. Even in the dark, the degradation rate increased with the increasing of temperature. It was as high as 92 % when the mixing liquid was kept at 60?¡ãC for 2?h. The high catalytic activity of the F-N-W-codoped TiO2 might result from larger specific surface area and high surface acidity because of surface F ions, the band gap narrowing caused by WxTi1?xO2 or O-Ti-N, as well as lower recombination rate of charge carriers because of valence variation of W ions (W6+?¡ú?W5+) in the forbidden band.
