Removal of Heavy Metal Ions from Aqueous Solutions by Adsorption onto ZIF-8 Nanocrystals

The adsorption of single heavy metal ions and competitive adsorption characteristics of binary heavy metal ions Cu2+, Cd2+, Ni2+, and Co2+ on Zeolitic imidazolate frameworks-8 (ZIF-8) nanocrystals were examined in batches. Rapid and preferential adsorption of Cu2+ suggests ZIF-8 as a novel candidate for removing copper ions in aqueous solution. ZIF-8@polyacrylamide (ZIF-8@PAM) composite microspheres with sub-millimeter-scale sizes were also successfully prepared, providing an easy route for the recovery of ZIF-8 nanocrystals used in Cu2+ removing.