TiO_2/粉煤灰光催化降解双氯芬酸钠研究

Photocatalytic degradation of diclofenac sodium over the photocatalyst of TiO_2 /CFA

以燃煤电厂外排的废弃物粉煤灰(CFA)为载体,采用混合泥浆法将TiO2负载在CFA的表面,得到一种新型的复合光催化剂TiO2/CFA.对TiO2/CFA进行了扫描电镜分析、X射线衍射分析和氮吸附测试,并以双氯芬酸钠的光催化降解为评价手段,研究了TiO2负载量对TiO2/CFA光催化性能及重复使用性能的影响.结果表明,TiO2负载量的增加有助于提高TiO2/CFA的光催化性能,但当TiO2负载量过高时,CFA上的TiO2在水处理过程中容易脱落,对TiO2/CFA光催化剂的重复使用性能不利.本研究中,最佳的TiO2负载量约为50%,循环使用6次,其光催化降解效率没有明显降低,双氯芬酸钠的降解率均可达70%以上.

A new type of composite photocatalyst TiO2/CFA was prepared by hybrid slurry procedure. Coal fly ash （CFA） discharged from coal-fired power plant was used as substrate, and the samples were characterized by scanning electron microscope, X-ray diffraction analysis and nitrogen adsorption tests. The impacts of loading amounts on the photocatalytic activity and re-use performance of titania anchored on CFA were evaluated by the photocatalytic degradation reaction of diclofenac sodium solution. The results show that the increase of loading amounts can improve the photocatalytic activity of TiO2/ CFA, but when the loads are too high, superfluous TiO2 are easy to break away from CFA in the progress of water treatment, which is not favorable for the re-use properties of photocatalyst TiO2/CFA. In this study, the optimal loading percentage of titania was about 50%, and the photocatalytic degradation efficiency was maintained at above 70% without any decline when the composite photocatalyst was used repeatedly, even in the sixth cycle.