Eficient removal of methylene blue from water using manganese-Prussian blue-carbon nanotube composite material (Mn/PB/CNT) for environmental remediation
摘要
A novel multifunctional nanocomposite, manganese-Prussian Blue-carbon nanotube, was synthesized through a facile and scalable method for its efficacy in the adsorption of methylene blue dye from water. The synthesis benefited from the combination of manganese redox activity, which offers additional coordination and electron-transfer sites, structural stability of Prussian Blue, and high surface area and conductivity of carbon nanotube in order to achieve optimum adsorption performance. Prussian Blue's structural stability, and the high surface area of carbon nanotubes to achieve optimal adsorption performance. The adsorption process was probed systematically through thermodynamic parameters. The findings revealed that dye removal was spontaneous, as indicated by the negative ΔG° value (− 6.46 kJ/mol), and exothermic in nature, as indicated by the ΔH° value of − 13.58 kJ/mol, with a loss in entropy (ΔS° = − 31.88 J/mol·K). The values suggest increased structuring and ordering at the solid–liquid interface during adsorption. The nanocomposite exhibited qmax of 31.2 mg/g and a removal efficiency of 91% under optimum conditions (pH 10, 25 °C, 15 min). The rationale endorses the unique contribution of Mn incorporation towards the formation of additional redox-active and coordination sites that complement PB and CNT in strengthening interfacial interactions between dye and adsorbent beyond the contribution of surface area. In general, the findings demonstrate that manganese-Prussian Blue-carbon nanotube nanocomposite is an extremely effective, low-cost, and eco-friendly adsorbent for the rapid elimination of cationic dyes from water. The success opens up avenues for the development of green nanocomposite-based technologies for wastewater treatment.