The Study On Preparation And Photoelectric Properties Of Titanium Dioxide Composite Coating By Electrophoretic Deposition

Titanium dioxide is a moderate price, high activities, chemical stability, safe and non-toxicity semiconductor material, so it is widely used in dielectric materials, photocatalytic materials and so on. TiO2 as semiconductor material has a wide application prospect in photoelectrochemistry field due to its unique photoelectric properties. However, the practical application of TiO2 is limited, because it is the lower utilization of solar light owing to its wide band gap (～3.2 eV), only to having UV light respondence. Therefore, the preparation of visible light responsed photocatalyst has been attracted much attention by electrochemical workers, and it is considered that coupling with other different level semiconductor material is one of the most efficient method for TiO2 photocatalyst to utilize visible light.In this paper, firstly, the synthesis of TiO2 powder was employed hydrolysis method of (C4H9O)4Ti, secondly, TiO2/different level semiconductor composite coating was deposited on ITO conductive glass surface. And then TiO2 composite coating was obtained by sintering treatment process, the surface morphology, elemental compostion, chemical composition, electronic band structuer and phase composition were characterized by SEM, EDX, FT-IR, UV-Vis DRS and XRD. Photoelectric properties of the composite coating electrode were measured in pH= 7.00 phosphate buffer solution (PBS) and on 0.50 mol·L-1 CH3OH as electroactive species in pH= 9.51 Na2CO3-NaHCO3 buffer solution as supporting electrolyte by CHI 660C electrochemical workstation, such as EIS, Tafel curve and CV, then the mechanism of the photoelectric properties of TiO2 composite coating electrode was discussed in the abstract. The main results and conclusion can be summarized as follows:(1) TiO2 composite coating was successfully deposited on ITO conductive glass surface by electrophoretic deposition, and the optimal process was confirmed to deposite these composite coating.(2) Subsquent treatment of TiO2 composite coating was sintered at 450℃, the crystal of TiO2 was not been change, ZnO existed in hexagonal wurtzite crystal, while GeO2 and CuS have not obvious diffraction peak, these were characterized by XRD.(3) TiO2/different level semiconductor composite coating not only greatly improved TiO2 to absorb ultraviolet light, but also it made spectral response extended to visible region, which was confirmed by UV-Vis DRS.(4) Photoelectric properties of composite coating electrode were measured by CHI 660C electrochemical workstation. EIS, Tafel curve and CV indicated that the composite coating electrode has taken on different photoelectrocatalytic activity under the different light source illumination and the doping amount of the semiconductor, respectively. The composite coating electrode has presented very significantly photoelectrocatalytic activity under 100 W incandescent lamp illumination. Compared with ultraviolet light, photoelectrocatalytic activity of the composite coating electrode was still lower under visible light irradiation.