2. Experimental 2.1. Chemicals Titanium tetrachloride (TiCl4) (99.99%) was purchased from Sigma Aldrich. Absolute ethanol (≥99.99%) was purchased from Merck Millipore (Germany).These reactants and the models pollutants HCOOH and phenol were obtained from Acros Organics and used without further purification. Commercial TiO2 P25 was obtained from Evonik. Ultrapure water (18MΩ.cm-1) was used throughout the whole experiments. 2.2. Synthesis of photocatalysts The TiO2 nanoparticles were prepared by the sol-gel method described below: 3.9 ml of TiCl4 was slowly added into 10 milliliter of absolute ethanol in reaction vesel, this reaction performed under fume hood at 0°C with vigorous stirring due to exothermic reaction,the high volatilityof TiCl4and also therelease of hydrogen chloride. Then, water was added dropwise during the mixing process. The above solution converts of colorless to yellow suspension solution which produced TiO2 nanopowder by drying process at 85°C in anstove for 15 hours. Finally, TiO2 nanopowder obtained were treated in furnace at different temperatures (400°C-800°C) for 2 hours. The initial heating rate was maintained at 5 °C/min. 2.3. Characterization 2.3.1 UV- Visible diffuse reflectance spectroscopy (DRS) The measurement of irradiance is used to know the light flux received by the photocatalysts. The measurements were …show more content…
The column was heated to 40 °C and coupled to a detector PDA-SPD-M20A detecting every 1.2 nm from 190 to 800 nm. The used eluent is a mixture of 85% water acidified to pH = 3 with H3PO4 and 15% nitric acidand the flow rate was set to 1 mL/min. The detection wavelength was set at 222 nm. The identification of intermediates by HPLC analysis was verified by comparing their retention time and the UV/VIS spectra of pure