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

Abstract

Inthiswork,disc-likehematite(Fe2O3)nanoparticleswerepreparedusingareadilyavailable inexpensive earth material, ferruginous laterite, via a low-cost synthesis route. Prepared hematite nanoparticles were characterized using X-Ray di raction (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 ofhematitenanoparticleswasevaluatedasaheavymetalionadsorbent. Batchadsorptionexperiments were conducted to study the adsorption behaviour of Ni2+ and Cd2+ 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 coe cient (R2) was used to determine the best fit kinetic model. Our data fitted the Langmuir kinetic model well and the highest adsorption e ciencies were found to be 62.5 mg/g for Ni2+ and 200 mg/g for Cd2+, respectively. Due to high surface area, pore volume with active sites, and sorption capabilities, hematite nanoparticles can be used as e cient and economical nano-adsorbents for the removal of Ni2+ and Cd2+ ions from industrial wastewater