Photocatalytic degradation of volatile chlorinated organic compounds on CuffiO_2 films prepared by size-controlled Cu deposition

尺寸控制铜沉积制备的 CuffiO_2 薄膜光催化降解挥发性氯化有机化合物

基本信息

批准号：
18550180
负责人：
YAMAZAKI Suzuko
金额：
$ 2.56万
依托单位：
Yamaguchi University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18550180/
关键词：
photocatalyst film metal-loaded TiO_2 materials for environmental remediation

项目摘要

Cu-deposited TiO_2 (Cu/TiO_2) films were prepared by photoreduction of Cu(II) in the presence of sodium formate. With the initial Cu(II) concentrations less than 50 mg L 1, the transmittance of the films decreased with an increase in the irradiation time. After the irradiation for 6 hrs, the scanning electron microscopy (SEM) indicated that the most of the Cu particles on the films were 0.51±0.04 μm. On the other hand, when irradiation was conducted in 100 or 150 mg L^<-1> Cu(II) solution, induction periods were observed before the transmittance decreased. The SEM images of the films indicated that Cu particles of 2.6±0.5 μm were deposited isolatedly with much open space in the induction periods. These facts proposed two methods to fabricate the Cu/TiO_2 films. The Cu amounts loaded on the film can be verified by changing the initial Cu(II) concentration less than 50 mg L^<-1> (method A), or changing the irradiation time within the induction period under the Cu(II) concentration above 100 mg L^<-1> (method B). The photocatalytic activities of the Cu/TiO_2 films prepared by both methods followed by calcination at 500℃ were compared in the degradation of methylene blue in aqueous solutions. The films prepared by method B showed a higher photocatalytic activity than a pure TiO_2 under no purging with air. This finding is attributable to higher transmittance of the films and function of the Cu particles as the electron trap which leads to suppression of the recombination between holes and electrons. Photocatalytic degradation of trichloroethylene (TCE) in the gas phase was also performed on the Cu/TiO_2 films prepared by method B. However, the TCE conversion decreased drastically with an increase in the irradiation time. This fact suggests that the accumulation of the by-products significantly affected the performance of the Cu/TiO_2 films.

通过在钠形式的存在下的Cu（II）来制备Cu沉积的TIO_2（CU/TIO_2）膜。随着初始Cu（II）浓度小于50 mg L 1，膜的传输随辐射时间的增加而降低。辐照6小时后，扫描电子显微镜（SEM）表明膜上的大部分CU颗粒为0.51±0.04μm。另一方面，当在100或150 mg l^<-1> Cu（II）溶液中进行辐射时，在传播下降之前观察到诱导周期。薄膜的SEM图像表明，在感应期间，将2.6±0.5μm的CU颗粒沉积在很大的开放空间中。这些事实提出了两种制造CU/TIO_2膜的方法。可以通过更改小于50 mg l^<-1>（方法A）的初始CU（II）浓度来验证膜上加载的CU量，或在cu（ii）浓度下在诱导期内更改辐照时间以上100 mg l^<-1>（方法b）。在水溶液中甲基蓝的降解中比较了通过两种方法制备的Cu/TiO_2膜的光催化活性。通过方法B制备的膜显示出比在没有空气清除下的纯TIO_2的光催化活性更高。这一发现归因于薄膜的较高传输和Cu颗粒的功能，因为电子陷阱会导致抑制孔和电子之间的重组。在通过方法B制备的CU/TIO_2膜上也进行了气相中三氯乙烯（TCE）的光催化降解。这一事实表明，副产品的积累显着影响了CU/TIO_2膜的性能。