TiO_2薄膜光催化还原Hg^(2+)的研究

Study on Photocatalytic Reduction Hg^(2+) by TiO_2 Film

采用溶胶法制备出TiO2、SO42-/TiO2、CdS/TiO2薄膜光催化剂,研究了TiO2薄膜光催化还原Hg2+的最佳实验条件以及SO42-/TiO2、CdS/TiO2薄膜与TiO2薄膜、TiO2粉体与薄膜之间的光催化活性差异.结果表明:当pH=5.34时,经30 min紫外光照射,Hg2+的还原率达到最大;Hg2+初始浓度越高,光致还原量越低;光源波长越短,Hg2+的还原率越高;当甲醇添加量达到15%(体积比)时,反应30 min后,Hg2+的还原率即达100%;CdS改性薄膜的光催化活性高于未改性薄膜;CdS/TiO2薄膜的光催化活性略高于粉体.

TiO2,SO4^2- /TiO2,CdS/TiO2 film photocatalysts were prepared by sol method. The optimum experimental conditions for photocatalytic reduction Hg^2＋ using TiO2 film and the photocatalytic activity comparision among SO4^2-/TiO2 , CdS/TiO2 , and TiO2 film, between TiO2 powder and film were investigated. The results were as follows： the best reduction efficiency of Hg^2＋ was obtained under UV irradiation for 30 min at pH= 5.34, the photoreduced mass of Hg^2＋ was more lower with the Hg^2＋ initial concentration increasing, the reduction efficiency was promoted under shorter wavelength, the reduction efficiency reached 100 % after 30 min at the additon of methanol = 15 % （v/v）, the photocatalytic activity of CdS- modified film was higher than that of unmodified film, the photocatalytic activity of CdS/TiO2 film was better than that of powder.