Nitrogen-Rich Magnetic Bio-Activated Carbon from Sericin: A Fast Removable and Easily Separable Superadsorbent for Anionic Dye Removal

Activated carbon materials are moving away from traditional simple carbon-based porous materials to high-performance and functional materials. Thus, various attempts have been made to improve the performance and process efficiency of the emerging materials by doping with various heteroatoms, introducing functional nanoparticles, and modifying these materials using polymer chemistry. In this study, N and O heteroatom-doped activated carbon materials were prepared by using silk sericin, a by-product of the silk industry, as a raw material; magnetic nanoparticles were introduced into the heteroatom-doped activated carbon to prepare high-performance and easily separable adsorbent materials. N-doped activated carbon having a high surface area of 3289.1 m(2)g(-1) was prepared by a simple and one-step chemical activated sericin carbonization process without the generally required additional N-doping process. The subsequent introduction of magnetic nanoparticles (MNPs) not only facilitated the separation of nitrogen-rich bio-activated carbon from the contaminant solution, but also enhanced the capacity for adsorption of the anionic dye, methyl orange (MO; 869.57 mg g(-1)), with a faster MO removal rate compared to that of N-doped activated carbon without MNPs. In addition, by simply varying the pH of the solution, effective adsorption-desorption-based recycling could be achieved. This MNP-containing N-rich activated carbon can be applied as a high-performance adsorbent for the remediation of wastewater streams as it affords excellent adsorption efficiency, a fast removal rate, and easy separation from aqueous solution.