阳极氧化法制备TiO_2纳米管形貌与光电催化性能表征—氧化时间因素控制

The Morphology and Photoelectro-catalytic Performance of Ti O_2 Nanotubes Synthesized by Anodizing Method-Oxidation Time Control

采用电化学阳极氧化方法,通过控制氧化反应时间制备了一系列Ti O2纳米管,采用SEM、XRD和XPS分别对Ti O2纳米管的形貌、物相结构和组成元素进行了分析,并研究了Ti O2纳米管的光电催化及光催化降解有机染料的反应活性。结果表明,氧化反应时间的增长会导致Ti O2纳米管的管径和长度增加,从而加快光生电子-空穴对的生成效率,提高催化活性;但氧化时间过长时会使Ti O2纳米管表面的规整度下降,表面缺陷增多,致使光生电子-空穴对的再结合速率提高,反而使催化活性降低;适宜的阳极氧化时间为120min。

A series of TiO2 nanotubes were prepared by anodizing method in different oxidation time. The morphology, crystal structure and the element composition of these TiO2 nanotubes were characterized by SEM, XRD and XPS, respectively. The corresponding photoelectron-catalytic and photocatalytic performance of the TiO2 nanotubes were studied by the photo-current density measurement and the photo-degradation of RhB. The results showed that the optimized anodization time was 120mins, at which the incident photon to current conversion efficiency （IPCE） of the TiO2 nanotubes reached 18%, and the reaction rate constant of the photocatalytic degradation of RhB reached 6×10^-3min^-1.