Preparation Of Nano-titanium Dioxide Film And Wastewater Treatment

As functional material, Nanometer TiO2film has many advantages, and has beenwidely used in many industry fields. Water is the source of human life, so to solve theproblem of water resource is a major social engineering. Photocatalysis of TiO2film caneffectively degrade the organic matter in laboratory simulation wastewater, printing anddyeing wastewater and fruit juice waste water.Pure TiO2films, TiO2film doping Ag Fe, Zn, Y, Bi and polyethylene glycol (PEG)were prepared using sol-gel method in this paper, and finally titanium dioxide thin films ofdifferent crystal type were formed at different calcination temperature. As the forbiddenbandwidth of TiO2is3.2eV, absorption wavelength range of pure TiO2film is small,smaller wavelength of ultraviolet light is needed to induce the photocatalytic reaction. Thedegradation efficiency of TiO2film doping different metals was compared in this paper.The doped metal can widen the absorption wavelength range, thus improving theutilization efficiency of the visible light. The results by thermogravimetry indicated that:decomposition curve tended to be balance when the temperature was over640oC,decomposition, and the surplus residue had transferred from anatase into TiO2of rutilephase; it was found that the characteristic peak of TiO2was at about530nm by FT-IR; theresult of XRD showed that when doping yttrium at500oC, the peak of anatase phase issharp and high without miscellaneous peak, which indicates that crystalline grain withyttrium is big and perfect with particle size in about20nm. In addition, rutile phase wasobserved, which is good for the photocatalysis; surface morphology of the film withrelatively uniform particle size prepared was scanned by electron microscopy (SEM), andthe surface smoothness was shown in this paper.By comparison of degradation efficiency of the TiO2films doping different metals, itwas found that the film doping yttrium performed best in degrading methylene blue, andthe performance of film doping yttrium was finally studied. It was found that layersnumber of TiO2film had a certain effect on the degradation efficiency, and4layers wasfinally determined to be the best thickness. In addition, different concentration of doped metals can result in different degradation efficiency of the photocatalysis, and finally0.15mol/L of yttrium concentration was determined. Overall, TiO2film doping metals hadhigher degradation rate than the pure one, and performed well in processing fruit juicewastewater.