Time-dependent adsorptive removal of methylene blue dye by CoFe₂O₄-rGO nanocomposite

Methylene blue (MB) contamination in water is one of the key contributors to many chronic health problems, making its eradication one of the most pressing challenges. We report the successful synthesis of cobalt ferrite-graphene nanocomposite (CF-rGO) to eliminate MB from water by adsorption. A facile solvothermal method was employed to prepare CF-rGO nanoadsorbents, and their physical and chemical properties were systematically investigated. The composite shows a saturation magnetization value of 27 emu.g^− 1, making it advantageous for the recycling procedure using magnetic separation. It is found that the CF-rGO composite exhibits an adsorption capacity of 15.5 mg.g^− 1 within 30 min, successfully removing 93% of MB from water. It further shows good recyclability, with a dye removal efficiency of 78% even at the end of the fifth cycle. The produced CF-rGO adsorbent is thus promising as it is simple to separate, has a high adsorption capacity, is recyclable and is inexpensive. It could be a good candidate for reusable adsorbents for effective adsorption and elimination of MB dye from aqueous solutions.