A facile hydrothermal synthesis, adsorption kinetics and isotherms to Congo Red azo-dye from aqueous solution of NiO/graphene nanosheets adsorbent

A series of NiO/graphene nanosheets adsorbents (NGNS) were synthesized by a facile hydrothermal method, and characterized by UV-vis, XRD, TG, TEM, HRTEM, Raman, SAED and XPS methods. The NGNS was applied to deal with wastewater solution containing Congo Red (CR); and adsorption efficiency attained 99.56% at optimum condition. The adsorption kinetic and isotherm of adsorbent toward CR were investigated. The results indicated that pseudo second-order kinetic model and the equilibrium data were well fitted by Redlich-Peterson model. The adsorbent can be separated from system effectively and easily. The prepared adsorbent has potential application for the wastewater treatment containing CR azo-dye. (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.