Preparation And Performance Analysis Of Composite Nano-Photocatalyst

TiO₂-based semiconductor photocatalysis technology has been shown to be potentially advantageous for environmental remediation as it may lead to complete mineralization of pollutants at ambient conditions with the use of ultraviolet light as the energy source. However, the large scale application of titanium dioxide as mutual photocatalyst is hampered by the fact that it absorbs only the very small ultraviolet part (4%) of solar light.In order to further enhance the TiO₂ photocatalyst activeness, this research uses the metallic oxide doping to modify TiO₂ .In this study, selected ZnO,Fe₂O₃ and SnO₂ have prepared the doping modification nanometer TiO₂ by using the sol-gel method and Supercritical Fluid Drying method.TiCl4 is the source of titanium,C2H5OH is the solvent.In the nature pH, the room temperature, the same dry ways, considered the roasting temperature how to influence the crystal composition, the particle size and the catalytic activity. And uses XRD to study the phase transition of the TiO₂ powder body in the roasting process,inspect the influence of various nonmetallic ion boron doping to crystalstructure and size of the TiO₂ powder body. Through the degradation dye solution, has studied boron to the titanium dioxide photocatylytical activity, has determined the best doping roasting temperature and the best doping quantity. The results showed:(1) The optimum doping of ZnO (mole fraction) is 0.5%, the photo-catalyst degradation rate of phenol in 6h reached 98.2% and COD reached 94.3%. (2)that the optimum doping of Fe₂O₃ is 3%, after calcination at 500℃for 2h. methylene blue absorbency degradation rate has reached 99.3 % after 3 hours.(3) the optimum doping of SnO₂ is 1%, after calcination at 500℃for 2h. Reactive Red X-3B absorbency degradation rate has reached 99.64% after 3hours and the removal rate of COD has reached 98.46%.Reactive orange K-NG absorbency degradation rate has reached 99.64% after 3hours and recycled catalyst can reach 98.46%. Reactive Violet X-2R absorbency degradation rate has reached 99.53% after 3hours and recycled catalyst can reach 84.79%.