Adsorption of industrial Acid Red 114 onto Fe3O4@ Histidine magnetic nanocomposite

Abstract

Fe3O4@ Histidine (Fe3O4@ His) magnetic nanocomposite (MNCs) was successfully prepared by simple thermal decomposition method. The final obtained products were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermogravimetric analysis, scanning electron microscope (SEM), and transmission electron microscopy (TEM). Powder XRD analysis confirmed the single phase of Fe3O4 spinel structure. SEM and TEM analysis indicated that Fe3O4@ His MNCs were nanoparticles-like structure with small agglomeration. FT-IR results revealed that L-histidine made a bond through its COO-group with Fe3O4 Nanoparticles (NPs). There is electrostatic attraction between cationic NH2 group (NH3+) of Fe3O4@ His MNCs and anionic dye. The Fe3O4@ His MNC has much higher adsorbed amount of Acid Red 114 (AR114) than the Fe3O4 NPs at pH 5 and 8. At pH -5 on the nanoparticle surface via ammonium groups. Thermal analysis showed the decomposition of the L-histidine capping. The hysteresis (sigma-H) curves revealed Fe3O4@ His MNC exhibit a typical super paramagnetic characteristic with a saturation magnetization of 45.5 emu/g. The adsorption capacity of low-cost and eco-friendly adsorbents Fe3O4@ His nanocomposite for removal of industrial AR114 from wastewater was investigated. Therefore, pH of 5 and contact time of 120 min were found to be optimum for maximum removal of AR114 by Fe3O4@ His MNCs. The experimental data of adsorption obey Langmuir isotherm and pseudo-second-order kinetic. The maximum adsorption capacity of the Fe3O4@ His MNC for AR114 was 140.8 mg/g at pH 5. The reusability of the Fe3O4@ His MNCs was also done, and significant removal of AR114 obtained even after five cycles. Thus, Fe3O4@ His MNCs considered as a good stability and reusability absorbent for the removal of industrial AR114.