Facile Fabrication and Characterization of Three-Dimensional Ordered Films of TiO2 Hollow-Spheres

High-quality three-dimensional ordered TiO2 hollow-spheres (3DOH-TiO2) materials were fabricated using polystyrene spheres colloidal crystals (ca. 290 nm in center-to-center distance) as sacrificial templates and titanium tetrachloride as titanium sources. The obtained samples were characterized by X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and N2 adsorption–desorption. The results showed that the films are composed of a closely packed, hexagonal array of the TiO2 hollow-spheres with a center–center separation of ca. 260 nm. The homogeneity in the shell thickness (ca. 40 nm), the physical contact among adjacent hollow-spheres, and the long-range order in the sample were also confirmed by FESEM and TEM analysis. HRTEM results indicated the walls of the hollow-spheres consist of anatase TiO2 nanoparticles (15–20 nm). The porous framework structure of the 3DOH-TiO2 films was further characterized using N2 physical adsorption, and the Brunauer–Emmett–Teller specific surface area and the total pore volume are around 77.72 m2/g and 0.262 cm3/g, respectively.