Synthesis of Carbon Nanosheets from Onion Peels for Removing Methylene Blue from Aqueous Environments

Background: Nowadays, colored water and, remarkably, wastewaters from dyeing industries are one of the most significant sources of toxic compounds in the environment. On the other hand, waste management and reduction are the most main obstacles governments encounter. Therefore, this study aimed to use waste materials to remove contaminants. Method: First, we pyrolyzed onion peels, added distilled water, and then sonicated the solution. AFM (Atomic force microscopy) analysis determined the characteristics of produced carbon nanosheets. Batch experiments on the synthesized carbon nanosheets implemented adsorption studies. The effects of adsorbent dose, pH, dye concentration, and temperature were also evaluated. Results: The isotherm assessments indicated that the data significantly matches the Langmuir model; moreover, the kinetic modeling results showed that the experimental data perfectly matched the pseudo-second-order kinetic model. Conclusion: Synthesized carbon nanosheets from onion peel as a low-cost adsorbent with good properties; not only are eco-friendly materials that can significantly reduce solid waste generation, but they are efficient adsorbents for methylene blue removal from aquatic solution.