Study Of Doped Nano-TiO₂Loaded Onto Activated Carbon Fiber Photocatalyst Material With Visible Light Activity

TiO2can lead to complete degradation of organic pollutants by photocatalyticoxidization at ambient conditions. However, TiO2is irradiated only with ultravioletlight (＜375nm) due to its large band gap, and nano-TiO2particles do can agglomerateevidently and is difficult to separate from the solution after degradation, which greatlylimits the practical application of TiO2photocatalysts. In this paper, nonmetalnitrongon doped nano-TiO2and loaded onto porous materials of activated carbon fibers(ACFs) felt could broaden the photoresponse to visible light range and overcome theproblem which the photocatalyst is difficult to separate from the solution afterdegradation and can enhance the photoactivity of photocatalysts. So the topic is veryimportant and necessary.Nitrogen-doped nano-TiO2loaded onto ACFs felt materials (N-TiO2/ACFs) wereprepared by sol-gel method with titanium tetrabutyl oxide as Ti source, urea as Nsource, and ACFs felt as matrix materials. The photocatalysts were characterized byX-ray diffraction (XRD), Scanning electron microscope (SEM), X-ray photoelect-ronspectroscopy (XPS), UV-Visible diffusive reflectance spectroscopy (UV-Vis DRS) andN2adsorption-desorption to analyze the microstructure and performance. The loadtechnique of the photocatalyst loaded onto the surface of ACFs was optimized. Assimulated dyeing three-level wastewater produced by weak acid brilliant blue A dyedyeing silk fabric technology experiment, the photocatalytic performance of nonmetalnitrongon doped nano-TiO2and loaded onto porous materials of ACFs felt has beeninvestigated.Experimental studies have shown that when the drying temperature was60℃and the calcination temperature was500℃, nitrogen-doped TiO2nano-powder ofN-TiO2/ACFs was anatase, and the particle size about15.3nm.The optimal load timewas7times, the maximum load quality of photocatalyst was0.27N-TiO2per0.5gACFs felt. The absorption intensity of TiO2loaded on the ACFs felt surface increasesobviously. The absorption band edge was up to618nm from446nm, and the Bandwidth was reduced to2.01eV from2.78eV; The N elements in the form ofsubstitutional and interstitial were doped into the surface of photocatalysts. Theinfluence of adsorption properties was small which load technology to the matrixmaterial; the specific surface area was changed1121.32m2g-1from1142.49m2g-1；SEMcharacterization was found that nitrogen-doped nano-TiO2can be firmly loaded on the surface of loading-body, and most of the photocatalyst particles were uniformlydistributed on the surface of the ACFs felt.In the different light irradiation,200ml simulated dyeing three-level wastewaterwas degradated by0.77g N-TiO2/ACFs prepared by sol-gel method. Experimentalstudies have shown that the degradation rate was89.5%under xenon lamp,93.1%under mercury lamp, and97.2%under metal halide lamp. In the visible lightirradiation,200ml simulated dyeing three-level wastewater was degradated by2.31gN-TiO2/ACFs material during180min. COD reduced to97.3mg/L from501.9mg/L,the COD degradation rate reached to80.6%。...