Preparation of iron oxide nanoparticles doped with divalent metal: Application for heavy metal removal from waste water

摘要

Hematite (α-Fe_2O_3) nanopowders were successfully prepared via a hydrothermal route. In the present study the effect of divalent metals M (Cu, Zn, Co and Ni) adding on the structural properties of the hematite is investigated. During powder preparation, the used solution was composed of 75% of iron chloride as iron source and 25% of M (Cu, Zn, Co and Ni) chloride. The morphology and microstructure of the synthesized nanopowders were analyzed by using scanning and transmission electron microscopy (SEM and TEM, respectively) analysis and X-ray diffraction (XRD). The XRD analysis reveals that no spinel phase was formed. Moreover, no secondary oxide phases such as CuO, ZnO or CoO are formed suggesting that these atoms are diluted in the hematite network. The TEM and SEM observations results, indicated that the prepared powder is mainly composed of agglomeration of homogeneous spherical grains with average size ranged from 140 to 280 nm. The prepared nanoparticles were tested in waste water treatment. The nanoparticles are added to a real polluted water extracted from the university. Inductively coupled plasma mass spectrometer (ICP-MS) was used to determine the elements amount in the water. The obtained results indicated that the based ferrite nanoparticles have reduced the amount of the contaminant heavy metals such as Pb, As, Cs and Al present in the waste water. We noticed that Co: Fe_2O_3 and Cu: Fe_2O_3 nanoparticles were more efficient, this is due to their lower cristallinity coefficient that enhances their specific surface and metal adsorption sites.