ELECTROCHEMICAL PROCESS FOR THE SYNTHESIS OF ANATASE TIOFROM IONIC LIQUID BASED ON CHOLINE CHLORIDE

摘要

The invention relates to an electrochemical process for preparing TiOas powder comprising nanocrystalline particles, said process using ionic liquids based on choline chloride as electrolyte, the titanium dioxide being used as semiconductor material in photoelectrical, photocatalytical and optical fields. According to the invention, the process consists in electrochemically dissolving a titanium anode under the action of a direct current of 2...5 A/dmfor 2...6 hours at a temperature in the range of 40...70°C in an electrolyte comprising eutectic mixtures of choline chloride and ethylene glycol in a molar ratio of 1:1 or choline chloride and urea in a molar ratio of 1:2, whereto there are added 0.004...0.006 M of tetrabutylammonium bromide and ethanol in a volume ratio of 2:1 and 1:1 as compared to the ionic liquid, thereby resulting an intermediary product which, after being separated from the reaction medium, is washed with ethanol, dried and calcinated at a temperature of 500°C, there resulting finally a TiOpowder as crystalline anatase with an anode formation output in the range of 85...97%, with particles sizes of 10...20 nm, with a specific surface of 60...90 m/g having an average pore diameter of 3.8 nm and a pore volume of 0.2 cm/g, the absorption in the visible light range having a maximum of 525 nm and a photocatalytic degradation efficiency of pollutant organic/inorganic compounds of over 90%.