Novel Fe doped mesoporous TiO2 microspheres: Ultrasonic–hydrothermal synthesis, characterization, and photocatalytic properties

Novel Fe doped mesoporous TiO2 microspheres were fabricated by an ultrasonic–hydrothermal method when tetrabutyl titanate was used as a precursor and octadecylamine was used as a structure-directing agent. The mesoporous materials were characterized by XRD, SEM, TEM, N2 adsorption–desorption measurements, XPS, FL, and UV–vis. The results suggest that both ultrasonic treatment and hydrothermal procedure are critical for the fabrication of Fe doped mesoporous TiO2 microspheres with a combination of regular morphology, large specific surface area, high crystallinity, and high thermal stability. Low-angle XRD and TEM images indicate that the disordered wormhole-like mesostructure of Fe doped TiO2 microspheres with diameters of about 300−400 nm is actually formed by the agglomerization of nanoparticles with an average size of about 10 nm. The photocatalytic activity of Fe doped mesoporous TiO2 microspheres was evaluated by the photodegradation of methyl orange. A small amount of Fe3+ can obviously enhance their photocatalytic activity. The optimal atomic ratio of Fe to Ti for photocatalytic activity is about 0.5 at%.