Synthesis of Fe3O4-Ag core shell nanoparticles using Cinnamomum verum bark extract and removal of methyl orange from aqueous media

Abstract

Green synthesis of Fe3O4-Ag core shell nanoparticles (CSNPs) was performed using Cinnamomum verum bark extract (CVBE) as the green solvent, reducing agent and capping agent. Aqueous solutions of AgNO3, FeCl3.6H20 and CH3COONa were used for the synthesis. The first formation of Fe3O4-Ag CSNPs was observed within 10 minutes of the reaction time. The result recorded from UV-Vis spectroscopy, Fourier Transform infrared spectroscopy (FTIR) and Energy dispersive spectroscopy (EDS) favours the biosynthesis and characterization of Fe3O4-Ag CSNPs. Scanning electron microscopy (SEM) reveals that the shape is nearly spherical and Transmission electron microscopy (TEM) confirms the shape as spherical and minimum size achieved is 19 nm. The capability of synthesised Fe3O4-Ag CSNPs for adsorption of methyl orange (MO) was tested in batches. It was observed that the process is pH dependent with maximum adsorption occurring at pH 6. The adsorption equilibrium was achieved after 120 min of contact time. The data observed was fitted one by one to three different isotherm models, viz., Langmuir, Freundlich and Temkin isotherm model to find the mode of adsorption. The process was best described by Langmuir isotherm. The adsorption kinetics was further analysed by using the pseudo-first-order, pseudo-second-order and the Weber-Morris diffusion model on adsorption data. The kinetic data of this adsorption obeyed pseudo-second-order rate equation.