Studies On The Preparation And Photoelectronic Characteristics And Photocatalysis Of Nanostructure TiO₂ Thin Films

In this paper, The nanostructure TiO₂ thin films was prepared by sol-gel method,the preparation of metal ion doping TiO₂ have been developed. The nanostructure TiO₂ films were characterized by XRD, UV-Vis spectra and AFM.Influences of microstructure of TiO₂ on the charge recombination and electron transport are introduced and studies on the photoelectronic characteristics and photocatalysis of nano-TiO₂ thin films.Firstly, the uniform transparent nanostructure TiO₂ thin films is obtained on the glass substrate by sol-gel method, in whice tetrabutyl titanate is used as the precursor, ethanol as the solvent, acetic acid and muriatic acid as the complexant. By studying the influence of the factors, the optimal preparing conditions is got as follows: the complexant is used acetic acid and the proportion of the materials n(Ti(OC₄H₉)₄):n(ethanol):n(H₂O)=1:28:8. The results showed that: the films were heated at 500℃for 2h in the air. The thin films was composed of anatase phase and the diameter was 8.14nm, the particles distributed on the surface of the films were homogeneous and their averge rougjness was 1.54nm.Secondly, the factors such as complexant ,dip coating times, reaction time, ultraviolet source, the initial cincenttration of Rhodamine B and so on, which influenced the nanostructure TiO₂ thin films photocatalysis are investigated. The results show that with the increase of deposited times ,the degradation efficientcy also increases, when deposited four times, the degradation efficiency is the best. Wth the prolonging irradiation time, fast decrease of maximum absorbance is observed in UV-visible absorption spectrum of Rhodamine B.The ultraviolet source play an important role in the reaction, the photocatalytic oxidation of Rhodamine B by TiO₂ thin films fits the first order kinetics. Thirdly, The reslutes of TiO₂ thin films doping Fe³⁺ shows that: The structures of TiO₂ also are anatase phase; The main absorption peak shifted to red and the adsoprtion1increased after doping; The particles distributed on the surface of the films were homogeneous and their averge rougjness was 2.8nm. The activity can be improved by doping. And the optimal preparing conditions is doped 0.075% Fe³⁺.