Graphene oxide decorated with cellulose and copper nanoparticle as an efficient adsorbent for the removal of malachite green

Abstract

In this study, the graphene oxide surface was modified by grafting of nanocellulose and copper nanoparticles to promote the surface charge and adsorption efficiency for malachite green (MG). The structural and configurational properties of GO-CEL-Cu were verified by UV/Vis, SEM, TEM, EDX and FTIR spectroscopy and confirmed the electrostatic interaction and hydrogen bonding between GO, CEL and Cu-NPs. TEM images confirmed the deposition of Cu-NPs size between 24 and 37 nm on the GO surface. The uniform fine particles size makes strong interfacial interaction with GO sheets result in efficient load transfer from the matrix to the hybrid. The variable parameters such as adsorbent amount, MG concentration, pH, time and temperature were investigated to achieve optimum experimental condition. The experimental data was justified by Langmuir isotherm model with adsorption capacity for GO, GO-Cu, GO-CEL, GO-CEL-Cu as 127.3, 149.2, 156.8 and 207.1 mg/g, respectively. The spontaneity and endothermic nature of the process were confirmed by negative Gibbs free energy and followed the pseudo-second-order rate equation. Additionally, positive values of enthalpy and entropy suggesting endothermic process and increase randomness during process, respectively. In conclusion, nanocomposite is capable to adsorb the toxic dye due to its well economic, eco-friendly, well adsorption rate and regeneration ability.