Green synthesis and characterisation of L-Serine capped magnetite nanoparticles for removal of Rhodamine B from contaminated water

This paper describes a green one-pot synthesis of L-Serine (L-Ser) capped magnetite nanoparticles (Fe3O4 NPs) and its potential application for adsorption of RhB dye from aqueous solution. The surface property, structure, morphology and magnetic properties of as prepared L-Ser capped Fe3O4 NPs were characterised through UV-Visible spectroscopy, Fourier transform-infrared spectroscopy, X-Ray Diffraction (XRD), scanning electron microscope, transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The XRD results were indicated the formation of high crystalline spinel type Fe3O4 NPs. TEM images were shown the spherical shape of L-Ser capped Fe3O4 NPs with particle size of 5.9 nm. The VSM curve showed the superparamagnetic behaviour of L-Ser capped Fe3O4. A plausible interaction mechanism of L-Ser and Fe3O4 NPs was also investigated. L-Ser capped Fe3O4 NPs due to its large surface area and a strong magnetism was shown potential adsorption efficiency towards RhB dye from aqueous solution. The adsorption isotherm data fitted well with Langmuir isotherm model and the monolayer adsorption capacity (q(e, exp)) was found to be 6.82 mg/g at pH 7.4 and 300 K. The experimental kinetic data fitted very well with the pseudo-second-order model. The thermodynamic studies reveal that adsorption efficiency is critically dependent on temperature.