Ultrafast Removal of Cadmium(II) by Green Cyclodextrin Metal–Organic‐Framework‐Based Nanoporous Carbon: Adsorption Mechanism and Application

Water contaminated with heavy metals has been identified as a significant threat to human health. Therefore, the development of safe and rapid water‐treatment techniques is necessary. We have synthesized an eco‐friendly γ‐cyclodextrin metal–organic framework (MOF)‐based nanoporous carbon (γ‐CD MOF‐NPC) material, conducted a comprehensive characterization of it, and found its rapid and effective Cd^II‐removal capacity. The γ‐CD MOF‐NPC could effectively sequester a majority of cadmium ions within one minute, and it still demonstrated excellent adsorption ability under various conditions, including different pH, adsorbent dosage, and coexistent ions. The maximum adsorption capacity was calculated to be 140.85 mg g^?1 by means of the Langmuir model. The adsorption was primarily due to the effect of ion exchange of oxygen‐containing functional groups, as determined by studying the ζ potential and Fourier transform infrared spectroscopy. Flow‐through experiments further proved the rapid Cd^II‐removal capacity and potential of the practical application of γ‐CD MOF‐NPC in water treatment according to the cytotoxic data.