[Studies on Ag-TiO2/KIT-6 composite nanosized photocatalyst].

In the present paper,ordered mesoporous silica (KIT-6) as support,nanosized TiO2 into KIT-6 was synthesized by titanium tetraisopropoxide hydrolysis. Then silver was loaded by deposition-precipitation method. Ag-TiO2/KIT-6 composite nanosized photocatalyst was firstly synthesized and a series of correlated catalysts were synthesized by the same preparation method. Methyl orange is presently adopted as a representative organic pollutant to evaluate the photocatalytic performance of the as-synthesized catalysts. The order of photocatalytic activity of the as-synthesized samples was found as Ag-TiO2/KIT-6Ag/TiO2TiO2/KIT-6TiO2Ag/KIT-6. Detailed characterizations were conducted by techniques including XRD,N2 physical adsorption,XPS,UV-Vis DRS and TEM. It was found that the Ag-TiO2/KIT-6 sample shows the highest photocatalytic activity,which should be attributed to the Ag-TiO2 heterojunction structure and higher BET surface area of the Ag-TiO2/KIT-6 sample. Ag-TiO2 heterojunction improves the separation of photogenerated electron-hole pairs,thus enhancing the photocatalytic activity;Ag-TiO2/KIT-6 sample possesses high BET surface area,which facilitates adsorption and transportation of dye molecules,also leading to higher photocatalytic activity.