تحضير و تشخيص دقائق كبريتيد الخارصين النانوية وتطبيقاتها في ازالة صبغة المثيلين الزرقاء من المحاليل المائية

Synthesis and Characterization of Zinc Sulfide Nanoparticles and its Application in Removal of Methylene blue Dye from its Aqueous Solutions

Summary

This work focused mainly on the synthesis and characterization of zinc sulfide nanocrystals using chemical precipitation approach. Zinc sulfide nanoparticles with quasi-spherical shape have been fabricated by controlling the concentration of the starting materials, reaction time and pH of the solution. The formation of zinc sulfide nanocrystals was confirmed through TEM, FE-SEM, XRD and EDX techniques. The band gap energy was measured from the UV-Vis spectrum and was found to be 3.8 eV, the observation of blue shift with respect to the bulk ZnS is attributed to the effect of quantum confinement. The adsorption behavior of ZnS nanoparticles was demonstrated and it was found that ZnS particles have the ability to adsorb methylene blue dye (MB) from aqueous solution. It was found that with increasing amount of ZnS in the dye solution, the removing for MB increased.

In the second part of this project, zinc sulfide nanoparticles were prepared using green methods. In this method, parts of plants are used as reducing agents and protecting agents rather than using chemical materials. Parameters such as the concentration of the extract and pH of the solution were modified to control the growth process of ZnS nanoparticles. The band gap energy was determined from the absorption spectrum and found to be 3.93 eV, which is in blue shift compared to bulk ZnS. FTIR spectrum identifies the functional groups that could be attached to the prepared ZnS particles. ZnS nanoparticles’ adsorption behavior was demonstrated, and it was found that a small amount of ZnS particles (0.1 g) are able to adsorb methylene blue dye (MB) from wastewater.