双效功能型复合光催化剂Ag/TiO_2/AC的制备及光催化活性

Preparation and Photocatalytic Activity of Ag/TiO_2/AC Photo-catalyst with Double Function

以硝酸银、四氯化钛及活性炭为原料,采用溶胶-凝胶法和浸渍法制备了3种复合光催化剂。通过TEM、XRD、BET和UV-Vis光谱对复合光催化剂的形貌、物相组成、比表面积和吸光性能进行了表征,并以甲基橙的脱色降解为模型反应,考察了样品的光催化性能。结果表明:其光催化活性大小顺序为Ag/Ti O2/AC>Ag/Ti O2>Ti O2,其中,Ag/Ti O2/AC由于具有895.21 m2/g的比表面积和Ag的负载改性而具有吸附、光催化双效功能,且对光的吸收扩展到可见光区,对甲基橙的最大降解率能达到95.2%。催化剂连续重复使用5次,Ag/Ti O2/AC对甲基橙溶液的脱色降解率均保持在90%以上。

Three kinds of composite photo-catalysts were synthesized by sol-gel and impregnation process using silver nitrate, titanium tetrachloride and activated carbon as raw materials. The physical and chemical properties of the prepared samples, such as morphology, phase composition, specific surface area and optical absorption properties, were characterized by using TEM, XRD, BET and UV- Vis techniques. Taking methyl orange degradation as a model reaction, the photo-catalytic activity of the obtained photo-catalysts was investigated The results indicated that the catalytic activity of the catalysts decreased in the order of Ag/TiO2/AC 〉 Ag/TiO2 〉 TiO2. Ag/TiO2/AC had double-effect function of adsorption and photo-catalytic, and the absorption spectra extended to the visible light region because of high specific surface area （ 895.21 m2/g） and silver-supporting modification. Moreover, the maximum degradation rate of methyl orange could reach 95.2%. Although Ag/TiO2/AC was repeatedly used for 5 times, the degradation rate of methyl orange still kept above 90%.