Adsorption of methylene blue from aqueous solution onto porous cellulose-derived carbon/montmorillonite nanocomposites

Biomass-derived amorphous carbon has received considerable attention in recent decades. In this paper, carbon/montmorillonite (CMt) nanocomposites were synthesized by a hydrothermal carbonization of cellulose and montmorillonite (Mt), and the adsorption properties were evaluated by the removal of methylene blue (MB) from aqueous solutions. The CMt was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Nitrogen adsorption-desorption isotherm, Scanning electron microscopy, and Thermal analysis. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data and the Langmuir, Freundlich, Redlich-Peterson and Sips models were applied to describe the adsorption isotherms. The results showed that the equilibrium adsorption data was found to fit better to the Redlich-Peterson adsorption model, and the adsorption capacity for the removal of MB on CMt was 138.1 mgs(-1). The kinetic process of adsorption could be described by the pseudo-second-order model. The porous structure of CMt was responsible for the adsorption of MB. But the adsorption ability could be improved by increasing pH. Lastly, the adsorption mechanism was obtained.