Synthesis of magnetically separable and recyclable magnetic nanoparticles decorated with β-cyclodextrin functionalized graphene oxide an excellent adsorption of As(V)/(III)

Abstract

Here, we report a magnetic nanoparticles (Fe3O4NPs) decorated with β-Cyclodextrins (CDs)-functionalized graphene oxide (GO) (β-CDs-GO@Fe3O4NPs) have been synthesized via chemical reaction, this adsorbent has number of hydroxyl & carboxyl group which shows excellent water dispersibility and superior magnetic property, additionally this can be utilized as an efficient adsorbent to enhance the adsorption of As(III)/As(V). The physicochemical properties of the adsorbent prior to and after adsorption of As(III)/As(V) were characterized extensively using Powder-X-ray diffraction (Powder-XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Thermogravimetric analysis (TGA), High resolution transmission electron microscopes (HR-TEM), Superconducting quantum interference device (SQUID), Zeta potential, Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopes & elemental analysis (SEM & EDX). Batch adsorption experiments were conducted to study the various factors such as effect of pH, isotherms, kinetics, thermodynamics were studied with a view to understand the adsorption efficiency, while the data of adsorption isotherms and kinetics were better fitted by Freundlich isotherm model and the pseudo second-order kinetic model, respectively. The free energy change ΔG0 decreased with increase temperature and the positive ΔH0 and ΔS0 values indicates that endothermic nature of adsorption and increased randomness at the adsorbent-solution interface. The mechanism of adsorption has been discussed in detail and these studies provide a simple method for the preparation of smart adsorbent. Regeneration of the adsorbent was accomplished by sodium hydroxide and this adsorbent could be reused with quantitative recovery of two adsorption-desorption cycles. In addition to that, efficacy of the potential novel adsorbent has been examined in the adsorption As(V)/As(III) from aqueous solutions.