Preparation And Properties Of Noble Metal Modified TiO₂Aerogels Use Ionic Liquid As Template

In recent years, environmental pollution is more severe during the industrialization process.We should use chemical method to remove the pollutant that can not be decomposed by microorganism. Among various chemical methods, the method with TiO2as a photocatalyst has got a lot of public attention. Howere, the TiO2powder is hardly to reclaim. Within the process of preparation of TiO2aerogel, the traditional sol-gel method always use supercritical drying to obtain the samples with large specific surface area, and the samples need heat treatment to transform into anatase or anatase mix with rutile. The high pressure equipment used in the process of supercritical drying is costly, and the specific surface area will be reduce after high-heat treatment which also increase the energy consumption.At present, many researchers are actively researching the modified methods to improve the photocatalytic activity, recoverability and expand the light absorption range. In this paper, the pure TiOi aerogels, the Ag-doped and Ag-Fe-codoped TiO2aerogels with anatase were successfully prepared with tetrabutyl titanate as Ti resource and ionic liquid (IL) of1-hexyl-3-methylimidazolium bromide ([Hmim]Br) as a template and aging solution by sol-gel method in a low temperature and normal pressures environment. In our study, we obtained the modified TiO2aerogels with anatase via ambient pressure drying at60℃, and the structure properties of the aerogels samples were characterized by XRD, SEM, FT-IR, BET and UV-vis DRS, the concludes as follows:(1)A11of the samples are anatase. The aerogels are provided with nano-mesoporous structure, the particle size is in the range of8～10nm, and the specific surface area is within the limits of204～227m2/g. The samples have a large specific surface area, narrower pore size distribution and excellent absorption property.(2) The dopant of Ag can improve the photocatalytic performance of TiO2, but have not much effect on its structural performances, specific surface area and light absorption property. The light absorption range expand to visible region with the increase of the amount of Fe, and the absorption intensity increase gradually. (3) The result of degradation of Reactive Brilliant Blue KN-R showed that the sample with the moalr ratio of Ag/Ti equals to0.008had the best photocatalytic activity. The degradation rate is up to93.25%under sunlight for2h. Ag-Fe-codoped titanium dioxide has the similar photocatalytic performance as Ag-doped sample.