Synthesis and characterization of SnO2, TiO2 and Ti0.5Sn0.5O2 nanoparticles as efficient materials for photocatalytic activity

Abstract : This work reports the synthesis of polydispersible SnO2, TiO2 and Ti0.5Sn0.5O2 nanoparticles via microwave-assisted polyol as an efficient method using diethylene glycol (DEG) and triethylene glycol (TREG) as solvent. The properties of as-prepared samples were investigated by X-ray diffractometry, transmission electron microscopy, diffuse reflectance and FTIR spectrophotometery, photoluminescence spectroscopy and N2 physisorption. The X-ray diffraction patterns of the samples were indexed on the anatase phase of TiO2 and cassiterite phase of SnO2 and Ti0.5Sn0.5O2. The TEM images show uniform isotropic morphologies with average sizes close to10 nm. The band gap is reduced for Ti0.5Sn0.5O2 and enhances visible light absorption, a shift resulting in the absorption threshold towards the visible spectral range, compared to pure titania and tin. Slight shifts to longer wavelength are attributed to the change in the acceptor’s level induced by the mixture of both oxides. The evaluation of the photocatalytic activity is carried out using indigo carmine (IC) as model of chemical pollutants in UV irradiation conditions. The photocatalytic decolorization of the dye follows a pseudo-first-order kinetics and the constant apparent rate was increased with the increase of the tin oxide content up to 50%.