Preparation And Characterization Of Tio₂ Nanoparticles Supported On Sericite

Nano-TiO₂ has been widely used in the field of photocatalysis because of its non-toxic,high catalytic efficiency and good chemical stability.However,there are some problems in the use of TiO₂,such as low photocatalysis efficiency and the difficulty of recovery caused by particle agglomeration,which restrict its industrial production.One of the effective ways to solve the above problems is to load nano-TiO₂ on the surface or structure of inorganic materials such as minerals.Sericite has a large specific surface area,and its layered structure has some characteristics of ion exchange and pillared,so it is a suitable carrier for TiO₂immobilization.At present,there are few researches on the photocatalytic application of nano-TiO₂ supported by sericite.The loading technology and methods are often complicated in operation,high in cost,difficult to be controled in process and easy to cause secondary pollution.In this paper,Composite Photocatalyst?S-TiO₂?loading Nano-TiO₂ on the surface of Sericite was prepared by wet grinding of sericite and nano-TiO₂?P25?in a stirred mill.The optimum experimental conditions are determined as follows:TiO₂?P25?composite ratio 40%,solid content 35%,ball material ratio 3:1,grinding speed 1000r/min and grinding time 60 min.The prepared S-TiO₂ is featured with TiO₂ uniformly loaded on the surface of sericite,and the chemical bond between sericite and TiO₂ is formed through the dehydrogenation of each other's surface.The dispersion of TiO₂nanoparticles on the surface of Sericite is significantly improved,and the anatase phase is the main phase,while the mixed crystal structure of anatase and rutile is unchanged.The degradation of methyl orange solution by S-TiO₂ under UV irradiation was studied.The degradation rate of S-TiO₂ was 96%and 99%respectively after UV irradiation for 20 minutes and 30 minutes,which was the same as that of P25.S-TiO₂has good degradation effect on methyl orange solution with concentration of 10-50ppm,especially on pollutants with lower concentration.S-TiO₂ has recyclability and reusability.After four times of reuse,the degradation rate of methyl orange with the same concentration and amount still remains 99%.TiO₂/pillared-sericite Composite Photocatalyst?S-P/TiO₂?was prepared by sol-gel process using pillared-sericite material modified by thermally activated,acidified,sodium and CTAB intercalation as carrier.TiO₂ in the composite photocatalyst is mainly anatase,wihle anatase and rutile are coexist.The degradation rate of S-P/TiO₂ reached82%and 95%in 30 min and 60 min respectively under UV-light.