Prepn process of nanometer crystal titania aerogel with high photocatalysis activity

Abstract

The preparation process of aerogel TiO2 with high photocatalysis activity includes the following steps: dissolving non-titanium alkoxide and titanium source in alcohol-water mixture solution through stirring; adding metered epoxide to obtain translucent lumpy alcohol gel of titanium oxide in minutes; ageing, supercritical drying and roasting to obtain nanometer crystal aerogel TiO2 block or powder with adjustable micro structure and specific surface area greater than 100 sq m / g. Where, the titanium source is titanium tetrachloride, titanium trichloride or titanium sulfate; the epoxide is ethylene oxide, propylene oxide, chloropropylene oxide or butylenes oxide; and the organic alcohol solvent is methanol, ethanol, isopropanol or tert-butyl alcohol. When used in degrading nitrobenzene and other sewage treatment, the aerogel TiO2 has photocatalysis activity as high as three times that of commercial P-25 photocatalyst.

Description

technical field [0001] The invention relates to a method for preparing a highly active nanocrystalline titanium dioxide powder semiconductor photocatalyst, and in particular provides a method for preparing nanocrystalline titanium dioxide airgel through a non-titanium alkoxide sol-gel route. technical background [0002] Titanium dioxide (TiO 2 ) Photocatalytic materials have very broad application prospects in the fields of solar energy storage and utilization, photochemical conversion, organic pollutant treatment, sterilization and disinfection, and ecological building materials, which has aroused extensive interest and interest from governments, industrial departments and academic circles around the world. focus on. For decades, especially in the past ten years, semiconductor photocatalytic materials have become the research focus and focus of scientists all over the world. There are more and more research papers and patents in this area, and thousands of research works ...

AI Technical Summary

Problems solved by technology

Using titanium alkoxides such as butyl titanate as raw materials, airgel TiO can be obtained by using the traditional sol-gel method combined with supercritical drying technology. 2 , this process not only has a long preparation cycle, but also usually needs to use titanium alkoxide as a precursor which is expensive and difficult to control the hydrolysis process (J Non Cryst Solids, 2004, 350: 314; J Mol CatalA, 2005, 229 (1-2) :145)

Cheap and easy-to-obtain non-titanium alkoxide precursors (titanium tetrachloride, titanium trichloride, titanium sulfate, etc.) 2 However, it is difficult to prepare alcohol-gels with good quality by using the traditional sol-gel process using ordinary mineral acids or alkalis as hydrolysis accelerators, and it is impossible to further obtain blocks with good quality and easy-to-adjust structural properties. Aerogel TiO 2

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