Effects of microwave drying on the microstructure and photocatalytic activity of bimodal mesoporous TiO2 powders

Bimodal nanocrystalline mesoporous TiO2 powders with highly photocatalytic activity were prepared by a hydrothermal method using tetrabutylorthotitanate as precursor, and then dried in microwave oven. The prepared samples were characterized by XRD, SEM, TEM, HRTEM and N2 adsorption–desorption measurement. The photocatalytic activity was evaluated by the photocatalytic degradation of acetone in air under UV light irradiation at room temperature. The effects of microwave drying on the microstructures and photocatalytic activity of the TiO2 powders were investigated and discussed. The results show that microwave drying not only promotes the growth of the pores but also greatly reduces the state of agglomeration within the powders. All the microwave-dried TiO2 powders show higher photocatalytic activity than Degussa P-25 (P25) and the TiO2 powders dried by conventional method.