Highly effective adsorption of crystal violet dye from contaminated water using graphene oxide intercalated montmorillonite nanocomposite

Abstract

Herein, graphene oxide intercalated montmorillonite nanocomposites were prepared by a facile chemical route and then used for the adsorption of crystal violet dye from contaminated water. Structural characterization of the nanocomposites were performed using Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy, zeta potential, X-ray diffraction, specific surface area and pore volume measurements. The isothermal data obtained using batch adsorption technique were fitted using Langmuir and Freundlich equations and it was found that the experimental data is well described by the Langmuir isotherm model with a very high adsorption capacity of 746.27 mg g−1. The kinetics of the adsorption process showed rapid dynamics and conformed to pseudo-second-order model with a correlation coefficient of R2 > 0.99. The influence of interaction time and initial dye concentration on the adsorption efficiency were also investigated. Additionally, thermodynamic studies revealed that the adsorption process was spontaneous and endothermic. Further, the results indicated that the synthesised nanocomposites adsorb crystal violet dye efficiently (∼96%) with a small decrease in removal efficiency even after five cycles of adsorption and could be employed in wastewater treatment for the removal of cationic dyes.