Nanocrystalline Ni doped α-Fe2O3 for adsorption of metals from aqueous solution

Nanocrystalline Ni doped Fe2O3 powders were prepared by high-energy ball-milling from powders mixture of Nickel metal (Ni) and hematite (α-Fe2O3) with balls to powders mass ratio of 10:1 and for different concentration. X-ray diffraction and vibrating sample magnetometer (VSM) are used to characterize the samples. Phase identification shows that the hematite remains and confirmed the formation of a secondary phase identified as NiFe2O4. The lattice parameters (a and c) of hematite phase increase with increasing Ni concentration indicating an isotropic lattice expansion. The obtained nanocrystalline powders were tested for toxic metals removal from aqueous solutions. It was found that Ni-doped Fe2O3 is a highly efficient sorbent for Cd, Co and Ni from aqueous solution, and the maximum quantities of the adsorbed Cd, Co and Ni concentration per gram of Ni-doped Fe2O3 are 65.46 mg/g, 43.29 mg/g, and 42 mg/g respectively. We showed that Ni-doped Fe2O3 with 15 wt% is a highly efficient sorbent for Cd, Co and Ni from aqueous solution, and this nanomaterial is more efficient to remove Cd (II), Co (II) and Ni (II) than Cr (VI).