Preparation and characterization of Ca-doped zinc oxide nanoparticles for heavy metal removal from aqueous solution

Nano zinc oxide (ZnO) and Calcium doped zinc oxide (CZ) nanopowders were synthesized by sol–gel method from zinc acetate di-hydrate and an adequate quantity of calcium chloride hexa-hydrate. Calcium doped zinc oxide (CZ) were prepared at different Ca concentrations from 1 wt% (CZ1) to 5 wt% (CZ5). The obtained nanopowders were characterized by transmission electron microscopy and X-ray diffraction. The objective of this work is to find a new and highly efficient nanomaterial for the adsorption of heavy metals from waste water. For this reason, the nanopowders were used to uptake heavy metals (Cr, Cd, and Ni) from aqueous solution. The obtained results show that the incorporation of Ca in nanoparticles zinc oxide (ZnO) increases the capacity adsorption of nanopowders and CZ3 is more efficient than the other Ca-doped samples. In this work we studied also the effect of pH and the pyrolysis temperature of the nanopowders on the removal of heavy metal ions from aqueous solution by CZ3.