The Research Of The Preparation And Characterization Of Compound Photocatalytic Materials And Its Photocatalytic Activity

Ever since Fujishima’s experiment of the discovery of thephotocatalytic splitting of water on TiO₂in1972, the TiO₂have beenattracted widely attention because of its potential utilization in dyeingwastewater. However, it is difficult to solve those problems in thepractical application. First, TiO₂absorbs in the UV regime, which isonly a small fraction of the sun’s energy （4%⁶%） has seriouslyaffected the sun’s energy utilization rate and restricted the photocatalytic properties indirect increases the expense of utilization indyeing wastewater. In order to extend the TiO₂to visible-light P dopedTiO₂has been used in this paper. Secondly, due to nano TiO₂has smallparticle size the photocatalytic has desirable performance, but someproblems arise during the practice process, such as the loss ofphotocatalyst, catalyst deactivation, which leads to lower photocatalystperformance and higher water treatment cost. To solve these problems,nano TiO₂supported on talcum powder, which is a kind of magnesiumsilicate and has stable chemical property and special structures.In this paper, the material’s photocatalytic activity and adsorptioncapability was analyzed by degradation rate of methylene blue dye. Themodified talcum powder was activated by nitric acid. The preparationconditions of talcum powder were investigated, such as nitric acidquality score, acid leaching temperature, roasting temperature, roastingtime on adsorption properties of talcum powder were discussed. Theinfluence of different reaction conditions on adsorption was investigated. The kinetics of adsorption of methylene blue was studiedby the statical adsorption experiment and discussed using thepseudo-first-order and pseudo-second-order model. The adsorptionmechanism was studied through the Weber-Morris curve. Theadsorption isotherm of adsorption process was discussed by using theLangmuir isotherm model and Freundlich isotherms model. Thepreparation conditions of P doped nano TiO₂potocatalyst wereinvestigated by the sol-gel method. Through orthogonal experimentaldesign, the effect of preparation conditions on optical activity andphotocatalytic degradation of organic pollutants were studied by visiblelight. The research conditions including roasting temperature, roastingtime, molar ratio of glacial acetic acid to tetrabutyl titanate, P and Timolar ratio, amount of adding water and ethanol. Target pollutant wasmethylene blue dye, which exhibits difficult biochemical degradablecharacters. The photocatalytic activity of potocatalyst was analyzed bydegradation rate. On the base of those experimental conditions, the Pdoped TiO₂was prepared by sol-gel method and supported on talcumpowder by isovolumetric impregnation method. The paper analysed anddiscussed the effects of different preparation technologies on theproperties of the compound photocatalytic materials, such as roasttemperature, roasting time, and loading of active component in catalystand reuse experiment. The results showed that when the roastingtemperature at550℃for2h, soaking time at12h the adsorptioncapability and photocatalytic activity of nano P doped TiO₂supportedon talcum powder is34.9%and76.7%, respectively. The crystal phaseand morphology of nano P doped TiO₂supported on talcum powderwere investigated by XRD, SEM and EDS. Meanwhile, this paper is anoverview about the nano P doped TiO₂supported on talcum powderphotocatalysis, including reaction mechanism, reaction effect,immobilization methods and mechanisms.