Method for preparing nitrogen doped nanometer titanium dioxide visible light photocatalyst

Abstract

The invention provides a method for preparing a nitrogen doped nanometer titanium dioxide visible light photocatalyst and belongs to the field of titanium dioxide photocatalysis. The invention aims to solve the problem of low catalytic activity and the collapse of porous channels in the preparation process in the prior catalyst. The method comprises the followings steps that: 1), inorganic titanate reacts with a nitrogen containing compound in the presence of a surfactant to generate a sediment, the reaction solution is stirred for 0.5 to 10h and then stood and aged for 0 to 48h; 2), the sediment is subjected to vacuum freeze drying to form a precursor of the nanometer titanium dioxide visible light photocatalyst; and 3), the precursor is calcined at a temperature of between 250 and 800 DEG C for 0.5 to 10h to form the nitrogen doped nanometer titanium dioxide visible light photocatalyst. The method can avoid the collapse of the porous channels, and the prepared catalyst has the advantages of high number of surface active sites, big specific surface area, high catalytic activity, and the like.

Description

technical field [0001] The invention belongs to the field of titanium dioxide photocatalysis, and in particular relates to a preparation method of nitrogen-doped nano titanium dioxide visible light photocatalyst. Background technique [0002] Since 1972, Fujishima and Honda reported the use of TiO 2 Since the single crystal electrode photolysis of water (Fujishima A.Honda K.Electrochemical photolysis of waterata semiconductor electrode.[J].Nature, 1972,238:37-38.), people have studied the semiconductor photocatalyst TiO 2 A lot of research has been done on the application. TiO 2 It has shown good development prospects in wastewater treatment, air purification, photochemical cells, and hydrogen production by electrolysis of water. As early as 1977, Frank and Bard began experimenting with TiO 2 Degradation of cyanide in water (S.N.Frank, A.J.Bard, J.Am.Chem.Soc.99 (1977) 303.), since then the application of TiO2 in the environmental field has aroused great interest. After...

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Problems solved by technology

However, the drying temperature of the preparation methods disclosed in the above-mentioned patents is relatively high, and there is a large amount of water or other alcohols in a liquid state between the pores of the titanium-containing precipitate. Due to the relatively large tension between the liquid surfaces, during the drying process, with the The evaporation of the precipitated pores is easy to collapse, resulting in a decrease in the specific surface area of ​​the final catalyst, a decrease in the active sites on the surface of the catalyst, and a decrease in catalytic activity.

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