Preparation of economical and environmentally friendly graphene/palygorskite/TiO2 composites and its application for the removal of methylene blue

A novel economical and environmentally friendly graphene/palygorskite/TiO2 (Gil/Pal/TiO2) composites adsorbent was prepared and characterized by X-ray diffractometry (XRD), Fourier transform infrared (FTIR), 142 adsorption/desorption isotherms, transmission electron-microscopy (TEM) and scanning electron microscopy (SEM). The GR/Pal/TiO2 was applied to removal dye methylene blue (MB) and the optimum conditions of adsorption were investigated. The obtained results indicated that when the dosage of GR/Pal/TiO2, reaction temperature and time of the composite are 15 mg/mL, 40 degrees C and 1 h, respectively, the adsorption efficiency can reach 100%. The adsorption kinetic of MB followed the pseudo-second-order model while the adsorption isotherm confirms to the Langmuir model. The adsorption process is spontaneous and endothermic by thermodynamic study. Compared with other different reported materials, the novel GR/Pal/TiO2 composite exhibits a high adsorption ability for MB removal. The obtained results demonstrate that the prepared GR/Pal/TiO2 composites are very promising material for the removal of MB from wastewater. (C) 2015 Elsevier B.V. All rights reserved.