Synthesis and characterization and photocatalytic activity of TiO2 powders

Titanium (IV) isopropoxide (TTIP) was used for preparing TiO2 nanoparticles by the precipitation technique. The precipitation was carried out following two experimental routes. In the first route titanium (IV) isopropoxide was mixing in ethanol, the solution obtained was heated at 60°C, then; glacial acetic acid and sulfuric acid were slowly added under constant magnetic stirring. In the second route titanium (IV) isopropoxide was mixed in ethanol, the solution obtained was heated at 60°C; then deionized water was added and finally hydrochloric acid was also slowly added. In both experiments a white precipitate was obtained, and then it was centrifuged, dried and calcined at different temperatures. To evaluate the photocatalytic activity, pellets were made from TiO2 powders. The TiO2 pellets were evaluated by the degradation of a methylene blue (MB) solution. The evolution of the MB concentration was monitored by a UV-vis spectrophotometer. The morphology and crystal structure of the powders were examined by Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD), respectively.