Synthesis of a novel bis Schiff base chelating resin for adsorption of heavy metal ions and catalytic reduction of 4-NP

A novel CPS-AA chelating resin containing bis Schiff base was prepared by the CPS with synthetic small molecular ligands. It has been used for the adsorption of heavy metal ions in wastewater. Ft-IR spectroscopy and the 1 H NMR spectrum proved the successful synthesis of Schiff base structure on the chelating resin. The results of adsorption experiments showed the maximum adsorption capacities for Cu (II), Pb (II) and Ni (II) were 3.74, 1.02, and 2.87 mmol/g respectively. The adsorption condition experiment proves that the material has excellent adsorption selectivity and reusability. The possible chelation mechanism was inferred to be four-tooth coordination, which is beneficial to the stretching of molecular chain and increases the adsorption capacity and stability of heavy metal ions. Finally, Cu-adsorbed composites (CPS-AA-Cu) were used as catalysts to explore the reduction and removal of 4-NP in an aqueous solution, and the results showed excellent catalytic performance.