Synthesis of Hematite Nanodiscs from Natural Laterites and Investigating their Adsorption Capability of Removing Ni2+ and Cd2+ Ions from Aqueous Solutions

摘要

In this work, disc-like hematite (Fe_(2)O_(3)) nanoparticles were prepared using a readily available inexpensive earth material, ferruginous laterite, via a low-cost synthesis route. Prepared hematite nanoparticles were characterized using X-Ray diffraction (XRD), inductively coupled plasma mass spectroscopy (ICP-MS), particle size analyzer (PSA), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and nitrogen adsorption-desorption analyzer. The performance of hematite nanoparticles was evaluated as a heavy metal ion adsorbent. Batch adsorption experiments were conducted to study the adsorption behaviour of Ni~(2+) and Cd~(2+) ions as a function of the amount of adsorbent, contact time, and pH. Adsorption data fitted to the linearized Langmuir and Freundlich kinetic models were compared and discussed. The correlation coefficient (R~(2)) was used to determine the best fit kinetic model. Our data fitted the Langmuir kinetic model well and the highest adsorption efficiencies were found to be 62.5 mg/g for Ni~(2+) and 200 mg/g for Cd~(2+), respectively. Due to high surface area, pore volume with active sites, and sorption capabilities, hematite nanoparticles can be used as efficient and economical nano-adsorbents for the removal of Ni~(2+) and Cd~(2+) ions from industrial wastewater.