Abstract
The recent interest in adsorption of pollutants on nanomaterials has been gaining widespread attention especially in the utilization of nanocarbon based composite materials. Herein, graphene oxide/silica/single-wall carbon nanotubes (GO/SiO2/SWCNTs) composite was successfully prepared by a hydrothermal method for the adsorption of Congo red (CR) dye from synthetic wastewater. The nanocomposite morphology was characterized by X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), and Energy-dispersive X-ray spectroscopy (EDX). The present study focuses on the adsorption performance of CR dye from aqueous solution on GO/SiO2/SWCNTs composite in terms of kinetics, isotherm, thermodynamics studies and optimization of factors such as pH, temperature, concentration and adsorption time. The results showed that a higher adsorption of CR was observed onto GO/SiO2/SWCNT composite at pH 3.0 as compared to that with SiO2 and SWCNT. Similarly, the maximum adsorption capacity of 456.15 mg g(-1) was achieved at optimum temperature 20 degrees C, time (330 min) and 300 mg L-1 CR solution concentration. The dye adsorption on the nanocomposite was found to be obeying pseudo-second-order rate equation. Thermodynamic parameters showed that the adsorption of CR dye was spontaneous in nature.