Design and synthesis of an efficient nanoporous adsorbent for Hg2+ and Pb2+ ions in water

An efficient nanoporous adsorbent for Hg2+ and Pb2+ ions in water has been synthesized from the interaction of aqueous NaH2C3N3S3 and Na3C3N3S3 solutions. The Raman spectra of the sample indicate that the S-S bonds have been formed by this interaction, and N-2 sorption isotherms together with TEM images indicate the presence of hierarchical nanopores (mesopores/macropores). Interestingly, this nanoporous sample exhibits excellent adsorption behavior of heavy metal ions in water, giving the adsorption capacity of Hg2+ and Pb2+ at 735.3 and 375.9 mg g(-1), respectively. The Hg2+ and Pb2+ sorption isotherms are typical Langmuir and their kinetic model follows the pseudo-second-order. These results indicate that the adsorption behavior of the Hg2+ and Pb2+ ions on the sample is chemical. More importantly, this sample can be recycled 4 times without obvious loss of the adsorption ability in water, which is very important for its industrial applications in the future.