Microemulsion-based synthesis of nanoscale TiO2 hollow spheres

Nanoscale TiO2 hollow spheres are prepared based on gelatine-filled reversed microemulsions. The resulting nanomaterial exhibits an outer diameter of 25-35 nm, a thickness of the sphere wall of 4-6 nm and an inner cavity of 15-20 nm in diameter. The as-prepared hollow spheres are characterized based on different electron microscopic techniques, infrared spectroscopy and optical spectroscopy. Thermogravimetry, X-ray powder diffraction and sorption measurements according to the Brunauer-Emmett-Teller analysis are used to elucidate the thermal properties as well as the specific surface of the hollow spheres. Finally, the photocatalytic properties of as-prepared TiO2 hollow spheres are studied. (C) 2011 Elsevier Masson SAS. All rights reserved.