The Study On The Controled Preparation And Characterization Of Nanosized TiO₂ Particles And The Performance Of Photocatalytic Decomposing Formaldehyde

Because of highly increased value, nanosized TiO₂ particles have been extensively applied in environment, information, materials, energy sources, medical treatments and hygiene, etc. Great concern and striking development have been made in the world in the past 20 years. Their production focuses in Western Europeand the northern America, and another bigger output in Japan and Korea. A wide range of research has been carried out in our country.The purpose of this disquisition is to produce Nanometer TiO₂ particles with good qulity,low cost,high efficiency.The contents of research include the study of the optimal reaction condition, the test and analysis of the major property of the self-producted nanometer TiO₂, the study of formaldehyde photocatalyze in the static experiment system and the continuous flow system.Nanometer TiO₂ particles were prepared by controled liquid phase methods The effect of reaction temperature, the dipping speed, the water dosage and the calcining temperature have been studied systematically. From the results of experiments, we draw the conclusions that the optimal reaction temperature is 50℃,the ration of tetrachloride is 20%, the dipping speed is 3s/drop, the water dosage is 80mL, the weight of salvolatile is 30g, the optimal calcining temperature is 350℃By choosing and analyzing the major property of self-producted nanometer TiO₂, the particle size is about 30nm, the crystal form is anatase, the purity is above 98.7%, the specific surface area is 229.77m²/g, the impurity content is below 1.6%, the water content is about 0.61%, the pH value is about 6, the apparent density is about 0.46 g/mL.The self-producted nanometer TiO₂ and P25 were used for the experiment of formaldehyde photocatalyze in the static experiment system and the continuous flow system, By choosing and analyzing, the photocatalyze decomposition effect of two catalyzers is good and the photo-catalytic efficiency of the static experiment system is higher than the continuous flow system. the photo-catalytic efficiency of two catalyzers is very close,but the effect of P25 is better than the self-producted nanometer TiO₂.