Kinetics, isotherms, and thermodynamic modeling of liquid-phase adsorption of Rhodamine B dye onto Fe/ZnO-shrimp shell nanocomposite

摘要

A cost-efficient nanocomposite was synthesized by sol-gel production of Fe3+-doped ZnO nanoparticles (Fe-ZnO) on a base of shrimp shell. Samples were characterized using X-ray power diffraction, Fourier transform infrared spectrometry, and scanning electron microscopy through energy-dispersive X-ray analysis. Experimental studies on the removal of Rhodamine B (RB) from an aqueous solution in batches revealed that the adsorption equilibrium was best represented by the Langmuir isotherm, with a maximum monolayer capacity of 83.81 mg g(-1) for RB. Kinetic data were well described by a pseudo-second-order kinetic model. Different thermodynamic parameters, that is, changes in standard free energy, enthalpy, and entropy, were also evaluated. It was found that dye adsorption into the nanocomposite was a spontaneous, exothermic, and physical reaction.