Amino-functionalized, crosslinked reduced GO@cellulose hybrid for MO dye removal: Experimental characterization and...

Wastewater from the textile industry often contains significant amounts of Methyl Orange (MO), which raises environmental concerns. This study investigates graphene oxide as a promising adsorbent for removing the anionic dye MO from hydrous solutions. The research involved a comprehensive analysis of a GO-EDA/cellulose composite. Graphene oxide (GO) was synthesized using Hummer's modified method and then covalently functionalized through a simple one-pot process with ethylene diamine (GO-EDA) as a coupling agent to graft cellulose. Several characterization methods were used to identify the material, including spectroscopy of Fourier-transform infrared (FTIR), microscopy of scanning-electron (SEM), powder X-ray diffraction (XRD), and spectroscopy of ultraviolet-visible (UV-Vis). The optimization of GO-EDA/cellulose adsorbent synthesis was also conducted using density functional theory (DFT). The composite was tested for its ability to decolorize MO dye. Key parameters such as sorption isotherms, kinetics, thermodynamics, contact time, concentration, dosage, and pH were evaluated. The composite demonstrated a monolayer uptake capacity of 169 mg/g under 25 °C and pH 3 with a minimum dosage of 10 mg, achieved within 100 min. The results suggest that the composite is effective in removing MO dye, with the adsorption kinetics following a model of pseudo-second order and fits by the Freundlich model.