Self-assembled magnetic microcrystalline cellulose/MoS2/Fe3O4 composite for efficient adsorptive removal of mercury ions (Hg2+)

Mercury ions (Hg2+) exist widely in industrial wastewater and the Hg2+-containing water may cause serious risk to aquatic organisms and human health due to the toxic effect and bioaccumulation characteristic of Hg2+. Despite the recent progress in adsorptive removal of Hg2+ from water, preparation of efficient and easily separated adsorbents for adsorptive removal of Hg2+ remains a big challenge. This work reports a simple approach to construct a stable and efficient composite adsorbent (m-MCC/MoS2) by self-assembly of microcrystalline cellulose (MCC), amine-capped Fe3O4 nanoparticles and carboxylic MoS2 nanosheets in water and followed by freeze-drying treatment. In addition to convenient magnetic separation capability, the resulted m-MCC/MoS2 also displayed fast adsorption rate, favorable selectivity and high adsorption capacity for Hg2+. The maximum adsorption capacity can reach 469.48 mg g-1, and meanwhile the adsorption process can be completed within 20 min. The prime adsorption mechanism is based on the strong interaction between S atoms and Hg2+. Additionally, the Hg2+-adsorbed m-MCC/MoS2 could be readily regenerated with fine reusability. This paper thus provides a promising strategy for fabricating applicable composite adsorbent for Hg2+ removal.