Effect of solvents on properties of the ultrasound assisted synthesized ceria nanoparticles and its performance as an adsorbent

The present study revealed a facile, ultrasound assisted ceria nanoparticle synthesis route by the reduction of cerium nitrate hexahydrate in different solvents at room temperature. The different solvents employed were methanol (MeOH), ethylene glycol (EG), water (aq) and isopropyl alcohol (IPA). The ceria nanoparticles were synthesized without the use of any capping agent in 20 min. The yield obtained was around 90% for the synthesized ceria samples. As synthesized ceria nanoparticles were characterized by X-ray diffraction (XRD), Field emission gun scanning electron microscopy (FEG-SEM), Brunauer Emmett Teller (BET) and zeta (ζ) potential in order to determine the influence of solvent on the physical properties of ceria nanoparticles. All the ceria samples illustrated a predominant spherical shape with the size in the range of 5–20 nm. It was found that interaction of the solvent with ceria nanoparticles in the presence of ultrasound plays an important role in modulating crystallite size, surface charge and its adsorption performance for a xylene milling yellow 6G dye. Among all the sonicated ceria samples, IPA mediated ceria exhibited highest positive zeta potential and hence was found to be proficient for the complete removal of dye in 15 min. Furthermore, the adsorption of the yellow milling dye on the surface of (IPA mediated) sonicated ceria sample has shown to follow pseudo-first order kinetic model. The non-sonicated sample (prepared in MeOH solvent without ultrasound) shows negligible dye adsorption while sonicated sample reveals 50% removal of XMY dye due to the difference in zeta potential values resulted from the cavitation effects.