Retracted: Controlled Synthesis of Hierarchically Mesoporous TiO2 Hollow Microspheres with High Photocatalytic Activity

Well-crystallized anatase-phase F-TiO2 hollow microspheres have been synthesized via a facile combination of sol–gel and solvothermal process. The microspheres exhibited a unique three-dimensional hierarchical architecture and demonstrated a significantly improved photocatalytic performance. The resulting sample was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, N2 adsorption, and an UV-Vis diffuse reflectance spectroscopy. On the basis of characterization results, we found that the excellent performances of the mesoporous F-TiO2 hollow microspheres in photocatalytic activities can be attributed to the combined effects of several factors, namely, the surface fluorination, the existence of accessible mesopores channels, and the increased light-harvesting abilities.