摘要
A new paradigm to remove toxic chromate anions from aqueous solution by crystallization of chromatewater clusters with imine-linked guanidinium cationic ligands is introduced.The guanidium-based cationic ligand was easily prepared through the imine condensation of an alde hyde and aminoguanidine hydrochloride.The cationic imine-linked guanidinium liga nd(BBIG-CI)showed a high re moval capacity(292.5 mg/g)in the solutions.Rapid decontamination of chromate anions from the wastewater by this cationic ligand was resulted from an instantaneous crystallization.The produced guanidium chromate salts have an extremely low solubility(Ksp,BBIG=8.19×10^9).Such superior removal performance of these mate rials was attributed to the cha rge-assisted hydrogen bonding between the cationic ligand and chromate-water hydrate anions,which was revealed by the single-crystal X-ray diffraction analysis and density functional theory(DFT)calculations.In addition,the succes s ful recove ry of the guanidium-based ligand makes it more attractive for real-world applications.
基金
the National Natural Science Foundation of China(Nos.21790374,21825601,U1732112,21876124)
the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
the Fundamental Research Funds for the Central Universities(No.2019QNA4047)。