Spray pyrolysis synthesis of mesoporous TiO2 microspheres and their post modification for improved photocatalytic activity

摘要： Mesoporous TiO2 microspheres were prepared by spray pyrolysis for photocatalysis. Post modification of TiO2 by heat treatment was performed to optimize its photocatalytic performance. First, spherical TiO2 particles with mesoporous structure were synthesized at pyrolysis temperatures of 500, 600, and 700 oC. After characterization by XRD, SEM, and N2 adsorption, a sample prepared at 500 oC was found to possess desirable properties for photocatalytic performance through post-modification. In methylene blue degradation, mesoporous TiO2 microspheres synthesized at 500 oC outperformed other microspheres. Furthermore, samples obtained by spray pyrolysis at 500 oC were calcined at various temperatures as a post-modification process. The sample calcined at 350 oC showed improved photocatalytic activity due to optimal anatase crystallinity and surface area.