Fabrication of superporous cellulose beads via enhanced inner cross-linked linkages for high efficient adsorption of heavy metal ions

Abstract One of the most important problems in adsorption of heavy metal ions is its slow adsorption kinetics resulting from the narrow pore structure of adsorbents. Herein, a novel superporous spherical cellulose adsorbent was fabricated by a facile yet effective preliminary chemical cross-linking strategy for high efficient adsorption of heavy metal ions. By this strategy, the neighboring cellulose chains were cross-linked and assembled into large cellulose clusters, by which unique superpores with the pore size of 0.5–1.0 μm were formed. Meanwhile, the preliminary chemical cross-linking method prevented the growth of cellulose crystallization, leading to the formation of more amorphous regions, which contributed to high specific surface area (152 m2 g−1). Further, the proposed superporous cellulose beads were modified with glutamic acid and then applied for adsorption evaluation. It was worth mentioning that the adsorbent displayed outstanding adsorption capabilities toward heavy metal ions (98.86 mg g−1 for Cu2+ and 102.29 mg g−1 for Co2+) and fast separation (equilibrium within 30 min). In addition, the cellulose beads also showed excellent recyclability and regeneration. Together with low-cost and eco-friendly cellulose support, the superporous cellulose beads are regard as green and sustainability, and have great potential for industrial application of heavy metal ions treatment.