Preparation of TiO2, Ag-doped TiO2 nanoparticle and TiO2–SBA-15 nanocomposites using simple aqueous solution-based chemical method and study of their photocatalytical activity

摘要

Nanocrystalline TiO_(2), Ag-doped TiO_(2) and TiO_(2)–SBA-15 nanocomposites have been synthesised using a simple aqueous solution-based chemical method. Nanocrystalline TiO_(2) was synthesised by calcining the precursor prepared by using ethylenediamine tetraacetic acid and TiCl_(3) in aqueous medium. Formation of crystalline phase (anatase, rutile or mixed phase) and crystallite size were found to be dependent on calcination temperature. To enhance the photocatalytic activity, Ag-doped TiO_(2) was synthesised by doping of Ag during the synthesis step of TiO_(2). TiO_(2)–SBA-15 nanocomposites were synthesised by impregnation method. Pure anatase TiO_(2) nanoparticle was formed in the amorphous matrix of the silicate SBA-15, even though the loading of the TiO_(2) in the silicate matrix was as low as 5?wt%. The synthesised materials were characterised using thermal analysis, powder X-ray diffraction method, surface area and porosimetry analysis, diffuse reflectance analysis and transmission electron microscopy. The photocatalytic property of the synthesised materials was investigated towards the degradation of methyl orange under sunlight exposure and monitored by UV–visible spectrophotometer. Ag-doped TiO_(2) exhibited enhanced photocatalytic activity than undoped TiO_(2). TiO_(2)–SBA-15 nanocomposites showed impressive photocatalytic activity even with 10?wt% TiO_(2) loading.