In this study, zinc oxide (ZnO) doped with Sn thin films were deposited on the glass substrate at 550 °C by dip-coating technique using the solution synthesized by sol-gel method. The structural, surface morphology, optical and photocatalytic property of thin films were studied. X-ray diffraction (XRD) analysis showed that the Sn-doping greatly changed the microstructure, morphology and optical properties of ZnO films, which may contribute to the enhancement of photocatalytic activity. Additionally, the photocatalytic activity was investigated using methylene blue  dye under solar irradiation, with has high UV index from 7 to 8. The results indicated that Sn-doped ZnO had a higher photocatalytic activity and Sn dopant greatly increased the photocatalytic activity of ZnO thin film.

Core shell magnetite nanoparticles (Fe3O4@C) as adsorbent for lead ions from aqueous solution were synthesized. The characteristics of the modified materials were analysed. It could also be shown that the adsorption isotherms were well described by the Langmuir model. The kinetic of the adsorption process was found to follow the pseudo-second-order model expression. Thermodynamic studies indicated that the adsorption process was feasible, spontaneous and endothermic.