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

Mesoporous TiO 2 microspheres were prepared by spray pyrolysis for photocatalysis. Post modification of TiO 2 by heat treatment was performed to optimize its photocatalytic performance. First, spherical TiO 2 particles with mesoporous structure were synthesized at pyrolysis temperatures of 500, 600, and 700 °C. After characterization by XRD, SEM, and N 2 adsorption, a sample prepared at 500 °C was found to possess desirable properties for photocatalytic performance through post-modification. In methylene blue degradation, mesoporous TiO 2 microspheres synthesized at 500 °C outperformed other microspheres. Furthermore, samples obtained by spray pyrolysis at 500 °C were calcined at various temperatures as a post-modification process. The sample calcined at 350 °C showed improved photocatalytic activity due to optimal anatase crystallinity and surface area.