Novel route to obtain self-doped TiO2 mesoporous nanoparticles as efficient photocatalysts under visible light

OCHOA RODRÍGUEZ, PABLO ALEJANDRO; BENZAQUÉN, TAMARA BELÉN; PECCHI, GINA ÁNGELA; CASUSCELLI, SANDRA GRACIELA; ELÍAS, VERÓNICA RITA; EIMER, GRISELDA ALEJANDRA

Materials

MDPI

Año: 2019 vol. 12

1996-1944

Titanium dioxide materials were synthesized using two di_erent methods. The samples were characterized by X-ray di_raction (XRD), UV?Visible di_usion reflectance spectroscopy (UV-Vis DR), Raman spectroscopy, N2 adsorption/desorption, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron spectroscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Although both kind of materials were found to have mesoporous structure and anatase crystalline phase, one of them was obtained from a synthesis method that does not involve the use of surfactants, and therefore, does not require calcination at high temperatures. This implies that the synthesized solid was self-doped with carbon species, coming only from the same source used for titanium. Then, the relationship between the presence of these species, the final calcination temperature, and the photocatalytic activity of the solids was studied in terms of the degradation and mineralization of an Acid Orange 7 aqueous solution, under visible radiation. A photosensitizing e_ect caused by the non-metal presence, that allows the solid to extend its absorption range, was found. Hence, a novel route to prepare C-modified photoactive mesoporous TiO2, simpler and cheaper, where neither a template nor an external carbon source is used, could be performed