Synthesis of β-cyclodextrin–chitosan–graphene oxide composite and its application for adsorption of manganese ion (II)

Abstract

A novel β-cyclodextrin–chitosan–graphene oxide (β-CD–CS–GO) composite material was fabricated, and its application as excellent adsorbents for the removal of manganese ion [Mn(II)] was illustrated. The structure and morphology of the β-CD–CS–GO composite material were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry. The composites could efficiently remove Mn(II) from aqueous solution. The adsorption experiment was carried out, and the optimum experimental conditions were determined. The highest adsorption efficiency can reach 96% at 0.020 g mL^− 1 of β-CD–CS–GO, temperature of 25°C and time of 3 h. The adsorption kinetics of the system was investigated, and the experimental data were well followed by pseudo-second order equation. The equilibrium data were used to simulate Langmuir and Freundlich isotherm models, and the results show that the adsorption system was in excellent correlation with the Freundlich isotherm model and the maximum adsorption capacity of Mn(II) reached 177.94 mg g^− 1. The thermodynamic parameters showed that the adsorption process was exothermic and spontaneous. The proposed method shows that the prepared β-CD–CS–GO could be applied to adsorb Mn(II) in wastewater treatment.

Keywords:

• Graphene oxide
• β-Cyclodextrin
• Chitosan
• Adsorption
• Bivalent manganese ion