纳米TiO2/硅藻土光催化降解蒽醌染料废水的研究

为提高光催化剂的稳定性,选取硅藻土为载体,以钛酸四异丙酯为前驱物,采用溶胶-凝胶法制备了TiO2/硅藻土光催化剂,并利用XRD、SEM、FT-IR等技术对其进行表征.以蒽醌染料弱酸性艳蓝RAW为目标降解物,考察了TiO2/硅藻土的光催化活性、最佳pH值范围及催化剂重复使用对光催化活性的影响.结果表明,所制备的TiO2为锐钛矿和金红石混晶型,平均粒径11nm,通过控制硅藻土加入量可以得到负载均匀的光催化剂.所制备的TiO2/硅藻土具有较强的光催化活性,对弱酸性艳蓝RAW的降解效果好于商品Degussa P25型TiO2,最佳pH值为4.0.该催化剂性质稳定,重复使用15次后,催化活性仅降低12.4%.

Photocatalytic degradation of anthraquinone dye wastewater with nano-TiO2/diatomite

In order to improve the stability of photocatalyst, TiO_2/diatomite was prepared by sol-gel method with titanium (IV) isopropoxide as precursor, which was then characterized by XRD, SEM and FT-IR. The photocatalytic activity of the composite was determined using anthraquinone dye weak acid brilliant blue RAW as model pollutant. Influences of solution pH and the photocatalyst-reused on photocatalytic activity were also investigated. TiO_2 coated on the surface of diatomite showed mixed crystal of anatase and rutile with an average particle size of 11 nm. The uniform TiO_2 coating could be achieved by controlling the amount of added diatomite. The TiO_2/diatomite demonstrated strong photocatalytic activity, and the decolorizing rate for weak acid brilliant blue RAW solution was higher than that for the Degussa P25-TiO_2. The optimum pH for photocatalytic reaction was 4.0. The TiCVdiatomite also showed strong stability, with its photocatalytic activity reducing only 12.4% after repeated use for 15 times.