Areca nut husk derived activated carbon and carbon quantum dots for effective removal of methylene blue from water

Organic pollutants in water pose a significant threat to global water quality and human health. This work addresses this issue by synthesizing activated carbon and carbon dots prepared from areca nut husk using eco-friendly hydrothermal methods. The carbon dots exhibit strong blue fluorescence with a peak wavelength of ~ 385 nm and a size of 7–8 nm. The activated carbon efficiently adsorbs methylene blue from contaminated water, with the adsorption process following the Langmuir isotherm model and proceeding via chemisorption. The effects of contact time, concentration of dye, adsorbent amount, pH, and temperature were thoroughly studied. The adsorption efficiency of the synthesis-activated carbon was found to be 193.80 mg/g. Further, the occurrence of RL(separation factor) between 0 and 1 confirms that the adsorption process of MB dye on the activated carbon is a favorable one. This research article provides a simple and sustainable approach to converting areca nut husk waste into dual value-added products, offering promising applications in water purification.