Adsorption of Cd2+ions on plant mediated SnO2nanoparticles

Plant mediated SnO 2 nanoparticles were synthesized by using SnCl 4 .5H 2 O as a precursor material. The nanoparticles were then characterized for BET surface area measurements, energy dispersive x-rays (EDX), scanning electron microscopy (SEM), UV–vis diffuse reflectance (DRS) spectra and x-rays diffraction (XRD) analysis. The successful synthesis of SnO 2 nanoparticles was confirmed by EDX analysis. The particle sizes were in the range 19–27 nm whereas the crystallite size computed from XRD measurement was found to be 19.9 nm. Batch adsorption technique was employed for the removal of Cd 2+ ions from aqueous solution. The sorption studies of Cd 2+ ions were performed at pHs 4 and 6. The equilibrium concentration of Cd 2+ ions was determined by atomic absorption spectrometer (flame mode). The uptake of Cd 2+ ions was affected by initial concentration, pH and temperature of the electrolytic solution. It was observed that the adsorption of Cd 2+ ions enhanced with increase in the initial concentration of Cd 2+ ions whereas a decrease in the percent adsorption was detected. From the thermodynamic parameters, the adsorption process was found spontaneous and endothermic in nature. The n values confirmed 2:1 exchange mechanism between surface protons and Cd 2+ ions.