The Preparation And Properties Of Nanosized TiO₂ And TiO₂-ZnO Photocatalytic Materials

Nanosized TiO₂ possess high photocatalytic activity,photoinduced hydrophilic-lipophilic,chemistry stability,and it have been applicated in the field of environmental protection,indoor air cleaning,and self-cleaning coating,and so on.It has attracted a great deal of attention by the field of photochemistry and photocatalytic. In recent years,the TiO₂ have some disadvantage in application,as they can only absorb little of the sun-light energy,the photoluminescence exciton compounds mostly, and they can be erodedeasily by light,and so on,complex semiconductor is good at improve their capability.In this thesis,nanosized TiO₂,ZnO,TiO₂-ZnO powders were prepared by sol-gel process,and nanosized TiO₂,ZnO,TiO₂-ZnO films were prepared on glass substrates by sol-gel process with spin-coating machine that was design by ourself.Samples were characterized by modern testing means,such as X-ray powder diffraction(XRD), atomic force microscopy(AFM),scanning electron microscope(SEM),and determined the chemical composition,the crystal type,the crystal size,element content,,film microstructure and roughness.The photocataly activity of TiO₂ films and TiO₂-ZnO films which have different amount of ZnO were compared by the photocatalytic degradation of methylic.The effects of processing parameters on photocatalytic degradation property of TiO₂ and TiO₂-ZnO films were systematically investigated.The result shows that complex ZnO film improve the photocataly activity of TiO₂ films,at the same preparation condition, the photocatalytic degradation of methylic were 35%,respectively which were higher than that of pure TiO₂(26%),The photocataly activity of TiO₂-ZnO films which have 8%of ZnO is best.In addition,annealing temperature and film layers effect the photocataly activity more strongly than annealing time.The photoinduced lipophilic property of TiO₂ and TiO₂-ZnO film obtained was investigated by C₆H₆.It is found that H₂O and C₆H₆ drop's contact angle became small when they were irradiated by ultraviolet radiation.It is indicated that TiO₂ and TiO₂-ZnO film possess high photoinduced hydrophilic-lipophilic property,which have 6%of ZnO is best.The result shows that the photoinduced hydrophilic-lipophilic property of TiO₂-ZnO film are superior to pure TiO₂ film,The photoinduced hydrophilic-lipophilic property of TiO₂ and TiO₂-ZnO film obtained by different parameters was investigated,the crystal type,the crystal size,element content,film microstructure and roughness affecting the hydrophilic-lipophilic property were systematically studied.The effect that different surface treatment means on the photoinduced hydrophilic-lipophilic property of TiO₂ and TiO₂-ZnO film was investigate.The adhesive force was evaluated by peel test.Scanning electron microscopy was used to investigate the micro-structure of TiO₂ film and particle,It is analysed that adhesive force mechanism combined with experiment results.We recognize that adhesive force between nanosized film is formed by physical and chemic adsorption of crystal with glass substrates,and the chemic adsorption is primary.Parameters such as annealing temperature,annealing time,film thickness affecting the adhesive force were studied systematically,and analysed reason.Finally,chemistry stability of TiO₂ and TiO₂-ZnO film was investigated by 5%HCl and NaOH liquor,the result shows that the chemistry stability TiO₂ film was better than TiO₂-ZnO film.