| Nano-Ti O2 is a new environmental protection technology of wastewater developed in recent years. However, nano-Ti O2 has large forbidden band width, which also has low visible light utilization rate and is easy to reunion and difficult to recycle in water. Nonmetallic element sulfur and nitrogen doping modification of nano-Ti O2 can expand the range of spectral response, improve the visible light catalytic activity. Nano-Ti O2 loaded on activated carbon fiber(ACF) ca n solve the separate problem of photocatalyst. Therefore, we prepare S-N-Ti O2/ACF composite material with high visible light photocatalytic activity.In this topic, exploring a new method which can prepare S-N-Ti O2 photocatalysts by sol-gel quickly. Using tetrabutyl titanate as the Ti source, urea as the N source, thiocarbamide as the S source. Research the temperature, p H value, dosage of deionized water and ethanol content on the influence of the sol- gel. And ACF as substrate, preparing the S-N-Ti O2/ACF composite material by sol- gel. The photocatalysts, ACF and composite material were characterized b y Fourier Transform Infrared(FT-IR), X-ray diffraction(XRD), UV-Visible diffusive reflectance spectroscopy(UV-Vis DRS), X-ray photoelect-ron spectroscopy(XPS), Scanning electron microscope(SEM) and Transmission electron microscopy analysis(TEM) to analyze the microstructure and performance. The best prepartion technology of S-N-Ti O2 and load technique of the photocatalyst onto the surface of ACF was optimized. The structure of the anthraquinone dye reactive brilliant blue L-KN-R and the azo structure of weak acid red RN dye degradation as the target degradation. Testing the photocatalysts and composite material degradation property on the different structure of dye solution. In addition, the adsorption and visible light catalytic degradation mechanism of dye solution was proposed.Results show that the shortest time of gel time when the sol-gel experiment temperature is 30℃, p H is 4, deionized water adding amount is 5m L, anhydrous ethanol dosage is 100 m L; The best S-N-Ti O2 made by dry gel calcinated at 450℃ for 4h has single anatase phase, with the average particle size of 13.928 nm, when the molar ratio of thiocarbamide, urea, and the butyl titanate is 0.5:1:1. The absorption band edge of S-N-Ti O2 is widened to 610 nm and forbidden band width is reduced to 2.03 e V, which widen the range of spectral response and has good visible light catalytic activity. The results of photocatalytic degradation of reactive brilliant blue L-KN-R dye solution and weak acid red RN dye solution show that when the dosing quantity of S-N-Ti O2 is 0.2g/100 m L and the initial concentration of dye solution is 10 mg/L, the degradation rate is 91.42%,89.14% respectively under 250 W metal halide lamp irradiating for 180 min.The best preparation technology for S-N-Ti O2/ACF composite material by sol- gel,The wet gel load time 3 min, drying temperature 80℃, calcination temperature 450℃, load 0.17 g and substrate material 0.42 g. The results of photocatalytic degradation of reactive brilliant blue L- KN-R dye solution and weak acid red RN dye solution is 94.02%,93.89% respectively under 250 W metal halide lamp irradiating for 180 min. Solving the problems which can easy to reunion and difficult to recycle in water. The reactive brilliant blue L-KN-R dye solution and weak acid red RN dye solution are degradated to N2,H2 O,CO2 and Na2SO4 by synergy of the absorbtion of ACF and visible light photocatalytic degradation of S-N-Ti O2. |
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