纳米复合ZnO-TiO_2晶体的制备及其光电催化性能研究

Preparation and photoelectrocatalytic behavior of ZnO-TiO_2 composite nanocrystallites

采用溶胶凝胶法制备了纳米复合半导体ZnO -TiO2 薄膜,并进行了结构和光电催化性能的测试。TiO2 薄膜对五氯酚溶液的光电催化降解结果表明:当输入正向偏压后,其光催化性能有较大提高。由于ZnO的掺入,半导体薄膜电极的光吸收能力增强;同时,Zn2+可能作为光生载流子的浅俘获中心,导致表面界面电荷转移加速,从而延长光生电子/空穴对的寿命并抑制其复合,有效地提高了TiO2 薄膜光电催化活性。

The nanocomposite semiconductor ZnO-TiO_2 thin films have been prepared by sol-gel process, their structure and electrochemically assisted photocatalysis are examined. The results of photoelectrocatalytic degradation of PCP solution by thin TiO_2 films indicate that a much higher photocatalytic activity can be obtained when an anodic bias is applied. The doping of ZnO gives an increase to PEC activity of titania film electrode, which is due to the better absorption ability of ZnO-TiO_2 film electrode. It is initially thought that Zn 2+ acts as surface-interface shallow trap and favors the suppression of photogenerated electron/hole pairs.