| TiO2photocatalyst was regarded as the most promising green catalyst, but the large band gap and low quantum efficiency limit its large-scale applications in industries and daily life. In this paper, N/F-TiO2powder was prepared by acid-gel method, using butyl titanate as precursor, ammonium fluoride and ammonium chloride as doping agents. The photocatalytic efficiency were evaluated by degradation of reactive red X-3B, it was found that the best ratio of doping Ti:N:F was1:20%:10%(molar ratio), and the best calcination temperature was350℃. The X-ray diffraction (XRD) results showed that the crystal type was a mixture of anatase and rutile crystal. The101crystal face grain size was7.2nm. X-ray photoelectron spectroscopy (XPS) analysis showed that, N element was mainly interstitial doped in N/F-TiO2, while F element existed in the TiO2with two forms including chemical adsorption and Ti-F. UV-Vis diffuse reflectance spectrum (UV-Vis DRS) analysis showed that red shift phenomenon of absorption spectrum occurred in N/F-TiO2. What’s more, the UV absorbance was also increased.In N/F-TiO2, N and F elements had synergistic effect to improve the performance of photocatalyst, reducing the energy of band gap and promoting the separation of photon-generated carrier. Using the prepared N/F-TiO2as the photocatalyst,150W visible light as the irradiation source and after120min photocatalytic reaction time, the decolorization rate of reactive red X-3B was as high as99.3%and TOC removal rate was72.4%. Through the research and analysis about the adsorption behavior between the photocatalys and target degradable substance as well as the relationship between the photocatalysis reactions, it was found that the acidic conditions promoted the N/F-TiO2adsorption ability to X-3B, and also could accelerate the photocatalytic reaction. The result also confirmed that the reaction obeyed pseudo first order, according with Langmuir-Hinshelwood kinetic model. |
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