Flower-Like α-Fe₂O₃ for Removal of Heavy Metals from Wastewater

In the present work flower-like, α-Fe₂O₃ were synthesized by ethylene-glycol mediated polyol method. The synthesized flower-like, α-Fe₂O₃ were separated cadmium (C^d2+) chromium (Cr⁶⁺) and lead ions (Pb²⁺) from wastewater. XRD pattern and FESEM images show the obtained sample is pure hematite and flower-like nanostructures average particle sizes 4.0 μm. The BET specific surface area was 47.55 m²g^-1. Adsorption experiments were investigated the adsorbent dose, influence pH of the metal ions, sorption times and initial concentrations of heavy metal ions. High efficiency of Cd²⁺, Cr⁶⁺ and Pb²⁺ removal occurred at pH 7.0, 3.0 and 5.5, respectively. The adsorption equilibrium study showed that the heavy metal ions adsorption of flowers like α-Fe₂O₃ followed a Langmuir and Freundlich isotherm model. The heavy metal ions adsorption equilibrium data were followed to the Langmuir model. The maximum adsorption capacities were 16.95, 22.22 and 25.64 mg g^-1 for Cd²⁺, Cr⁶⁺ and Pb²⁺ ions respectively. This work determines that the synthesized flower-like α-Fe₂O₃ is proposed as an efficient nano-adsorbent for wastewater treatment.

Morphological, Magnetic and Optical Properties of α-Fe₂O₃ Nanoflowers

We report the morphological, structural and magnetic properties of the flower like iron oxide α-Fe2O3 samples prepared by the polyol method. The α-Fe2O3 samples were prepared by using different amount of the iron chloride in the starting materials and the impact of the different iron chloride amount on the morphology of the precursor and after heat treatment of the samples was investigated. The X-ray diffraction (XRD) analysis confirmed the formation of the α-Fe2O3 phase without detecting any impurity phase. The transmission electron microscopy (TEM) and the field emission scanning electron microscopy (FESEM) results showed that the flower like structures are composed of nanopetals with an average thickness and width of 60 nm and 735 nm respectively. A strong impact on the formation of the flower like iron oxide and the morphologies of these samples was observed with the variation of iron chloride concentration during synthesis process. The magnetic hysteresis measurements demonstrated that as prepared samples displayed ferromagnetic behavior and magnetic properties were found to be depending on the morphologies of as-prepared samples. The band gap energy was measured by using Tauc's method, and values for all the samples were found to be in the range 1.94-2.27 eV. The results obtained in the present work show that the α-Fe2O3 can be used as potential candidate material for use in gas sensors, photocatalysis and energy storage devices.