Efficient adsorption of cationic dyes using eco-friendly synthesized graphene oxide: A performance comparison and application perspective

This study demonstrates a reproducible and environmentally conscious method for synthesizing graphene oxide (GO) using a modified Hummers’ approach integrated with hydrothermal treatment. The synthesis process reduces hazardous chemical usage, shortens reaction time, and eliminates high-temperature post-treatment, making it more suitable for scalable production. The resulting GO material exhibits high adsorption capacities for two common cationic dyes, methylene blue (MB) and methyl green (MG), reaching 622 mg/g and 584 mg/g, respectively. Characterization by XPS, SEM-EDS, FTIR, zeta potential, and BET confirmed the presence of abundant oxygen-containing functional groups and a significantly increased surface area (167.36 m²/g), enhancing dye interaction. Adsorption followed pseudo-second-order kinetics and fitted well to the Langmuir isotherm model, suggesting chemisorption and monolayer surface coverage. GO retained over 44.91% of its adsorption efficiency for MB and 34.54% for MG after six reuse cycles, confirming its practical reusability. This study offers a feasible pathway toward low-impact, scalable production of GO for industrial wastewater treatment applications, aligning with current sustainability goals in environmental engineering.