Microemulsion-mediated hydrothermal method for the synthesis of mesoporous materials

NATALIA HASSAN ; VALERIA VERDINELLI; PAULA MESSINA; JUAN MANUEL RUSO

Oporto

Congreso; 4th Iberian Meeting on Colloids and Interfaces; 2011

Titanium dioxide (TiO2) and silica-based nanomaterials have been prepared through reactive microemulsion precipitation. The materials nano-powders were characterized by X-ray diffraction, FT-IR, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), UV-Vis and fluorescence spectroscopy. The results obtained by different process conditions show cuboids, around 90 nm in size, have a uniform and dense surface morphology with a band gap energy (2.30 eV) 1.39 times inferior to the anatase dominated by the less-reactive {101} surface (3.20 eV). On another hand for silica-based nanomaterials we obtained 3D opals-CT materials with an unusual fibrous microstructure similar than those existed in the nature and interesting optoelectronic characteristics. By this method, we demonstrate the reation of very long fibrils of 30-50 nm diameter and more than 20 μm length showing simultaneous short and long wavelength light emissions and band gap values (5.50 eV and 4.41 eV) comparable to those obtained for silicon based metal-oxide-semiconductors.