Recovery of beta-Carotene on Graphene Nanoplatelets UiO-66 Nanocomposites

Abstract

Recovery of beta-carotene from n-hexane solution onto Zr-based metal organic frameworks (UiO-66)/graphene nano platelets (GPNPs) has been investigated. The nanocomposite has been characterized by X-ray diffraction, scanning electron microscopy, specific surface area (Brunauer-Emmett-Teller) analysis, particle size distribution analysis, and Fourier transform infrared spectroscopy methods. The highest adsorption yield was found to be approximately 60% under optimum conditions (0.01 g of UiO-66/GPNP for the adsorption of approximate to 8 mg L-1 beta-carotene solution at 150 rpm mixing speed of the shaking bath). The relevant adsorption system was an endothermic, nonspontaneous, and chemisorption process depending on the kinetics (pseudo first order, pseudo second order, fractional power, and Elovich models), equilibrium (Langmuir, Freundlich, Redlich-Peterson, and Radke-Prausnitz isotherm equations), and thermodynamic parameters.