Electrochemical synthesis and photocatalytic properties of Al_2O_3-ITO-TiO_2 system film

0. TiCl_4水溶液电解。0. 1摩尔/升，在10 V/cm的电场强度下，在致密氧化铝/掺锡氧化铟（ITO）阴极和碳阳极之间进行。复合阴极溶解在溶液中，并在电极表面析出TiO_2。采用SEM、XRD、EPMA、拉曼光谱、紫外-可见光谱和XPS等测试手段对薄膜的结构进行了分析。随着加热温度的升高，薄膜表面生成的TiO_2由非晶态向金红石型转变。在200 ~ 800 nm的宽波长范围内，沉积的TiO_2薄膜能有效地吸收光子能量。在pH 5的草酸溶液中，Pt丝与TiO_2的沉积膜之间存在光电流。同时，草酸在两个电极上的分解（C_2O_4^<2->+2 □→2CO_2，2 H ^+2 e ^-→H_2）也得到了加速。

Electrolysis of TiCl_4 aqueous solutions of 0. 0. 1 mol/l was carried out at 10 V/cm of electric filed strength between dense alumina/tin-doped indium oxide(ITO) cathode and carbon anode. The composite cathode dissolved in the solution and was precipitated with TiO_2 on the surface of the electrode. SEM, XRD, EPMA, Raman spectra, UV-vis spectra and XPS were used to analyze the structure of the deposited film. The structure of TiO_2 formed on the surface of the film changed from amorphous to rutile with an increase in heating temperature. The deposited film with TiO_2 absorbed efficiently the photon energy in the wide wavelength range from 200 to 800 nm. The photocurrent flowed between the deposited film with TiO_2 and Pt wire in oxalic acid solutions at pH 5. 8 and accelerated the decomposition of oxalic acid at both the electrodes(C_2O_4^<2->+2□→2CO_2, 2H^+2e^-→H_2).