Simple synthesis of NH ₂ -functionalized Fe2O3 and its activated carbon composites for removing heavy metal ions

The novel recyclable and biodegradable absorbents NH ₂ -Fe ₂ O ₃ and NH ₂ -Fe ₂ O ₃ /oxidation-activated carbon (NH ₂ -Fe ₂ O ₃ /OAC) with great physical properties and high adsorption for uptake heavy metal ions were synthesized in this work. The NH ₂ -Fe ₂ O ₃ samples were prepared via one-pot hydrothermal methods, typically, FeCl ₃ •6H ₂ O, ethylene glycol and sodium acetate anhydrous were directly dissolved under stirring, followed by x mL of DETA and 0.1 g of SDS at room temperature (x = 0.5, 1, 2, 3, 4 and 5 mL). The as-prepared NH ₂ -Fe ₂ O ₃ were added into the mixture of oxidation-activated carbon, followed by the cation surfactant CTAB. After reflux condensation, the composites were washed, dried and labeled name NH ₂ -Fe ₂ O ₃ /OAC. Systematically characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR) and X-ray diffraction (XRD), physicochemical properties were all indicated obviously in this paper. The high adsorption rates of the adsorbents achieved over 88.11 % and 98.25 % towards Pb(II). In the ternary solution, the studied heavy metals revealed selective removal sequence: Pb(II) > Cu(II) > Cd(II).