TiO_2薄膜光催化还原Hg~(2+)的研究

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.

Study on Photocatalytic Reduction Hg2 + by TiO2 Film

TiO_2、SO_4~(2-)/TiO_2、CdS/TiO_2 film photocatalysts were prepared by sol method.The optimum experimental conditions for photocatalytic reduction Hg~(2+) using TiO_2 film and the photocatalytic activity comparision among SO_4~(2-)/TiO_2,CdS/TiO_2,and TiO_2 film,between TiO_2 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/TiO_2 film was better than that of powder.