The Preparation Of The Base Of Titanium Dioxide Photocatalyst And Its Research For Degradating Simulating Dye Wastewater

Using different biomass materials such as the powder of melon seeds, peanut shells, poplar leaves as template to prepare nano-sized TiO2 and TiO2 composited Ag3PO4 by hydrothermal method, using scanning electron microscopy (SEM),FT-IR, UV, XRD, thermogravimetric (TG) for the characterization, the degradation experiment takes methylene blue as the research object. The main contents are as follows:(1 Researching parameters such as different templates,hydrothermal temperature, hydrothermal time, calcination temperature and the optimum conditions for the preparation of TiO2 were using melon skin as template, hydrothermal 4h at 160℃ and calcined 4h at 700 ℃.(2)The results of the catalyst characterization show that:The particle size of TiO2 is from 30nm-50nm; the proportion of rutile increase when calcination temperature become higher.(3)Through studying catalytic conditions such as different TiO2 dosage, initial concentration of methylene blue, the concentration of Cl", adding oxidant such as H2O2,NaClO to research factors which can influence the photocatalytic activity of TiO2 under uv light. The experimental results show that the optimum amount of TiO2 is 0.6 g/L; TiO2 catalyst can degradate methylene blue solution whose concertration around 10 mg/L within 10 min; the concentration of Cl- has a definite impact on the degradation; the degradation rate increased by nearly 10%by adding oxidant.(4)The study for the mechanism of photocatalytic reaction showed that:TiO2 photocatalytic reaction mechanisms is the result of the combined effects of the hydroxyl radical and the direct hole oxidation, but the direct hole oxidation is the mainpart.(5)Based on the exploration of the preparation conditions and reaction conditions for the composited material, the optimum preparation conditions for composite materials are:pH= 7,ultrasonic 30 min,the ratio of the Ag3PO4 and TiO2 is 1:5; the best reaction conditions are:the amount of catalyst is 0.1 g, the dye concentration is 7.5 mg/L, add H2O2, NaCIO can shorten the time of the reaction equilibrium, shorten nearly 10 min.(6)The study for the photocatalytic properties of the composite material show that the light responding of the new photocatalyst has a very big enhancement, the light responding is not limited to the uv light,the degradation rate can reach more than 95% under visible light; the stability also improve after compositing.