Abstract：In order to improve the stability of photocatalyst, TiO2/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. TiO2 coated on the surface of diatomite showed mixed crystal of anatase and rutile with an average particle size of 11 nm. The uniform TiO2 coating could be achieved by controlling the amount of added diatomite. The TiO2/diatomite demonstrated strong photocatalytic activity, and the decolorizing rate for weak acid brilliant blue RAW solution was higher than that for the Degussa P25-TiO2. The optimum pH for photocatalytic reaction was 4.0. The TiO2/diatomite also showed strong stability, with its photocatalytic activity reducing only 12.4% after repeated use for 15 times.
