Solvothermal preparation of nanocrystalline anatase containing TiO2 and TiO2/SiO2 coating agents for application of photocatalytic treatments

This paper reports on TiO2 and TiO2/SiO2 materials prepared by a sol–gel process under solvothermal conditions with process temperatures between 120 °C and 180 °C. Under the preparation conditions chosen, the formation of anatase crystallites starts at a process temperature of 160 °C, as observed by X-ray diffraction. From TiO2 and TiO2/SiO2 sols coatings on viscose fabrics and powders have been prepared. The photoactivity of both materials – coated textiles and powders – is determined by the decomposition of the dye AcidOrange under UV light illumination. Significant dye decomposition is only observed for samples containing a high ratio of TiO2 and that are solvothermally prepared at 180 °C. In contrast, when the photoactivity is determined in presence of H2O2 totally different results are obtained and the degree of AcidOrange decomposition is higher for most of the samples. Furthermore, in presence of H2O2 the dye decomposition is observed even without UV light illumination. Especially samples prepared with the polymer Pluronic P123 under lower solvothermal process temperatures exhibit strong dye decomposition without illumination in presence of H2O2. Therefore, these materials could be of high interest for cleaning waste water containing dye stuffs from textile industry.