| 摘要 |
PURPOSE: Provided is a novel method of making photocatalytic titanium oxide sol by improving the existing hydrolysis process of sol-gel method. It is a method of making acidic titanium oxide sol and basic titanium oxide sol, inducing the crystal growth of anatase type at high temperature and pressure. The above titanium oxide sol for the photocatalyst has excellent properties of dispersion and coating and photocatalytic ability to decompose various organic materials. CONSTITUTION: The method comprises hydrolyzing, with 10-200mol.(based on a mole of titanium oxide) of water, the starting organic and inorganic titanium materials such as tetraethoxy titanium, tetraisopropoxy titanium, tetrabuthoxy titanium, titanyl chloride, titanyl sulfate and titanyl oxysulfate; crystal growing process of the above hydrolyzed titanium aqueous solution by adding inorganic acids, making a pH 0.1-2.5 solution, such as nitric acid, hydrochloric acid, sulfuric acid and hydrogen fluoride or 0.1-3.0mol (based on a mole of titanium dioxide) of amines such as trimethylamine, monoethylamine, diethylamine, triethylamine, tri-n-butylamine, tetramethylammonium hydroxide, tetraethyl ammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide and putting into the hydrothermal reactor and reacting at 80-210deg.C under 3-50 atm. for 1-48 hours for the acidic titanium oxide sol and 20-250deg.C, under 10-100atm. for 1-48 hours for the basic titanium oxide sol; and the third process of adding to the obtained basic titanium oxide sol of pH 9.5-13.0, 20-80wt.%(based on the wt. of water) of non-volatile organic solvents such as ethylene glycol or polyethylene glycol and eliminating water and amine by Dean Stark device to control the pH to 7.0-8.0 and the concentration of titanium dioxide.
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