Synthesis and characterization of S nO 2 nanoparticles: Effect of hydrolysis rate on the optical properties

Nanocrystalline SnO 2 oxides particles have been successfully synthesized via polyol process using diethylene glycol (DEG) as a solvent, followed by powder thermal treatment. The general ap plicability of the process is shown and the advantages in terms of properties and processability are described. The powders thus prepared were investigated using X - ray diffractometry. (XRD), scanning electron microscopy (SEM), transmission electron microsc opy (TEM), and photoluminescence spectra (PL). The X - ray diffraction patterns of the samples were indexed to the rutile phase for SnO 2 .The TEM images show uniform isotropic morphologies with average sizes close to10 nm. This decrease in particle size is ac companied with a decrease in the band - gap value from 3.55 eV for SnO 2 down to 3.27 eV as shown by UV - visible spectra. It is demonstrated that the crystallite size less than 10 nm can be controlled by changing the quantity of added water (rate hydrolysis h= n H 2 O/n Metal).