Synthesis and characterization of Fe3O4@TSC nanocomposite: highly efficient removal of toxic metal ions from aqueous medium

Abstract

In the present study, trisodium citrate (TSC) modified magnetite (Fe₃O₄) nanocomposite was synthesized and characterized using various analytical techniques. The transmission electron microscope images show that the Fe₃O₄@TSC nanoparticles are well dispersed due to the presence of the TSC coating on Fe₃O₄, and the particles sizes are in the range of 5–10 nm. The S_BET and the total pore volume of Fe₃O₄@TSC are 245.42 m² g⁻¹ and 0.368 cm³ g⁻¹, respectively. The saturation magnetization values of Fe₃O₄ and Fe₃O₄@TSC are 78.4 and 55.4 emu g⁻¹, respectively. The Fe₃O₄@TSC is a magnetic adsorbent and was used for the removal of Cr³⁺ and Co²⁺ metal ions from aqueous medium. The adsorption of both metal ions onto Fe₃O₄@TSC is rapid and efficient. The adsorption process is performed at diverse temperatures and the outcomes are investigated kinetically. The results show that adsorption was exothermic and followed the pseudo-second-order kinetic model. Isotherm modelling reveals that the Langmuir equation described the adsorption of both metal ions. Moreover, the loaded Fe₃O₄@TSC could be recovered easily from aqueous solution by magnetic separation and regenerated by simply washing with 0.1 M HCl solution. Consequently, Fe₃O₄@TSC nanocomposite could be utilized as an efficient and recyclable adsorbent for the removal of toxic metal ions from aqueous solution.