Study On Sol-gel Preparation And Photocatalytic Activity Of Titanium Dioxide Potocatalyst

This text using Ti(OCH9)4 as raw material,ethanol without water as solvent and nitric acid as inhibition, adopted three front joint of three factors and three standards designed arranged TiO₂ optimum preparation condition of experiment and characterized with XRD.Red colourant matter as objective degradation, research the effect of calcinations temperature,calcinations time,the height of UV lamp,TiO₂ concentration,pH of red dyestuff on photocatalytic degradation efficiency. The experiment result shows that TiO₂ preparation in this method is Nano-anatase. The most degradation effect is calcinations temperature 450℃,calcinations time 150min,10cm height of UV lamp,2g/l TiO₂,pH 4.The optimum process was obtained by measuring the absorbance value of the system, the effects of species concentration to the gelling reaction were investigated, and thereby,a fit reaction kinetic model was estimated. From the experimental results, the reaction rate constant is 0.23×10⁸mol?m^-3at room temperature,3.14×10⁸mol?m^-3at 33℃. Apparent activation energy is 247.7KJ ?mol-1.In this text, in order to further improve the degradation efficiency, iron metal zinc,copper,silver and chromium are added in TiO₂. Discuss its influence on degradation efficiency. The results shows that, the highest degradation of single commix achieve above 98%, and yet the highest degradation of pure titania only achieve 63%. The commixion of quantity of metal ion zinc,copper,silver,chromium separately is 5%,3%,3%,2%,5%,the degradation is very good, all of them achieve above 90%.The degradation of zinc(3%) and ge(5%) can achieve 96.88%. In the commixed of silver and copper, silver(5%),copper(1%),its degradation can achieve 91.45%.In the commixed of zinc(1%),silver(5%),its degradation can achieve 95.81%.In the commixed of zinc (3%),ge(5%),chromium(3%),its degradation can achieve 90.65%.This text also add rare earth element in TiO₂ to improve its activity. Discussed photocatalyst activity of four kinds rare earth (La,Nd,Y,Eu) doped TiO₂ in different dopant and time. Discussed influence of different dopant degradation organism pollutant of wastewater on the photocatalytic reaction. The result of this study show that rare earth element ions doping TiO₂ can restrain TiO₂ transform from anatase to rutile; increase the light absorption; restrain the recombination of charge carrier. The degradation rate is 98% when rare earth ions add in TiO₂,while pure TiO₂ degradation is only 63%.