Study Of The Preparation And Photocatalysis Of HPA Doped TiO₂ Film

Nanocrystalline titanium dioxide finds a broad field of realized and potential applications in the areas of photocatalysis. Nowdays,the chief problem of photocatalysis is how to enhance the activities and the stability of TiO2 photocatalyst,and ions-doped is one of useful methods to improve TiO2 activities.In this investigation,considering the photooxidation and charge transfering of HPA, PW/TiO2 film are prepared via sol-gel with tungstophosphoric acid(PW) as doped agent.The structure and crystal shape are studied via various measure.Photocatalysis activitise and kinetics analysis are investigated by photodegradating 4-chlorophnol(4-CP).The major research includes the following aspects:(1) The sol for TiO2 and PW/TiO2 film is prepared with tetrabutyl titanate as prescursor and alcohol as solvent,the film is obtained by dip-coating method.The parameter affected on crystal such as sintering temperature,PW doped etc have been studied via XRD, UV-Vis and so on,the results indicate that the major crystal shape of catalyst is anatase type, the shape of single TiO2 after high temperature sintering is rutile type.The type of PW still keeps Keggin structure after doping,and PW increase transformation temperature from anatase to rutile, different doped contents also influence on transformation .(2) Photocatalysis activitise of TiO2 and PW/TiO2 film are studied the relation bentween exploring PW content,sintering temperature,4-CP initial concentration,pH value and degradation ratio by photodegradating 4-CP solution.The result indicates that the best of degradation condition is n(PW):n(TiO2)=0.010:1, sintering temperature 600℃, 4-CP initial concentration 30mg/L and pH=5.The nature of film is stabilization,and the films can repeating use.PW obviously promote the activitise of titania.(3) The sol for TiO2 and PW/TiO2 film is prepared with tetrabutyl titanate as prescursor and acetic acid as solvent,the film is obtained by dip-coating method.The result of XRD,SEM,UV-Vis indicats that catalysts of the anatase structure are prepared at low temperature. The type of PW still keeps Keggin structure after doping,PW inhibites the growth of crystal grain.The film of 0.020:1 doped content and 480℃saintering has the highest activitise.