1Division of Environmental Technology, The Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
2Nanotechnology National Center, The National Science and Technology Development Agency (NSTDA), Pathumthani, Thailand
3Department of Chemical Engineering, Faculty of Engineering, Thammasart University, Pathumthani, Thailand
4Division of Environmental Technology, School of Energy, Environment and Materials, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
*E-mail: pummarin01@hotmail.com
Online published on 5 April, 2012.
The TiO2-MCM-41 thin films were prepared by two different processes; ex-situ and in-situ process, with the molar ratio of MCM-41 and TiO2 as 50:50. The ex-situ thin film was synthesized by mixing un-calcined MCM-41 (using rice husk silica as a silica source) with titanium precursor, whereas the in-situ thin film was synthesized from a mixture of MCM-41 and titanium precursors. The prepared thin films were then applied for treatment of gaseous BTEX (benzene, toluene, ethylbenzene and xylene). The experiment was conducted in a batch reactor equipped with UV source and the remaining gas was analyzed by GC/FID. Adsorption and photocatalytic mechanisms were studied under dark and UV irradiation. The TiO2-MCM-41 composite film was obtained from the ex-situ method. While, the in-situ TiO2-MCM-41 thin film had new hybridized crystal containing Ti-O-Si bond which plays an important role in the enhancement of photocatalytic degradation of gaseous benzene under UV irradiation. The overall photocatalytic degradation of gaseous benzene at the equilibrium state were 92% and 94% for the ex-situ and in-situ TiO2-MCM-41 thin film, respectively. The photocatalytic degradation of gaseous benzene, toluene, ethylbenzene and xylene by the in-situ TiO2-MCM-41 thin film was 65, 71, 76 and 82%, respectively.
TiO2, thin film, MCM-41, Photocatalytic reaction, Benzene, BTEX
