TiO_2薄膜的低温制备及有机半导体对其光催化活性的提高(英文)

Low-Temperature Preparation of TiO_2 Films and Enhancement of Their Photocatalytic Activity by Organic Semiconductor

采用具有锐钛矿晶粒的TiO2溶胶,通过浸渍提拉的方法,在载玻片上低温制备了具有光催化活性的TiO2薄膜。为进一步提高薄膜的光催化活性,采用掺杂了聚苯乙烯磺酸盐的聚乙撑二氧噻吩作为TiO2薄膜的涂膜基底,采用SEM、PL光谱等测试方法考察了该有机半导体基底对TiO2薄膜性能的影响,并就TiO2薄膜厚度对两种基底上薄膜光催化活性的影响及其机理进行了讨论。结果表明:电子从有机半导体向TiO2的迁移使得光生电荷较好地分离,从而增加了表层TiO2的空穴浓度。同时发现合适的TiO2厚度能够有效地提高薄膜的光催化活性。

TiO2 film was prepared on the microscope slide by dip-coating process using the TiO2 sol, which contained anatase crystalline grains. This film had photocatalytic activity directly without an annealing step in a typical sol-gel method. With an attempt to enhance the photocatalytic activity of the TiO2 film, poly（3,4-ethylenedioxythiophene）/poly（styrenesulfonic acid） （PEDT/PSS, an organic semiconductor） film was used as a substrate of the TiO2 film. To understand the beneficial effect of PEDT/PSS to the photocatalytic activity of the TiO2, scanning electron microscopy （SEM） and photoluminescence （PL） emission spectra were adopted. The effect of the thickness of TiO2 film on the photocatalytic activities of the two kinds of films and their photocatalytic reaction mechanisms were also discussed. The results show that the PEDT/PSS layer induces a better charge separation due to electron transfer from TiO2 layer to PEDT/PSS layer, and thus increases the amount of the hole in the superficial TiO2 layer. The appropriate thickness of TiO2 layer is effective for improving the photocatalytic activity of TiO2.