Ethylenediaminetetraacetic acid-functionalized graphene electrode for efficient recovery of Lead using capacitive deionization

Lead (Pb 2+ ), a heavy metal contaminant, poses serious environmental and health risks, necessitating efficient removal strategies. This study presents a novel asymmetric capacitive deionization (CDI) architecture made of ethylenediaminetetraacetic acid (EDTA)-functionalized graphene for efficient recovery of Pb 2+ from water. The EDTA-functionalized graphene electrode enables selective Pb 2+ chelation, while sodium ion is removed via electrostatic adsorption. The contact angle measurements signify the hydrophilic nature of EDTA-functionalized graphene electrode, and EDTA enhances the wettability of the electrode. Further, the CDI experiments show significant salt adsorption capacity, 465 mg/g for Pb 2+ , and 140 mg/g for sodium ion at initial concentration of 1000 mg/L, and an applied voltage of 1.4 V, attributed to the strong binding affinity of EDTA for divalent ions. The study also demonstrates excellent regeneration and cycling stability over multiple adsorption–desorption cycles. These results highlight the potential of EDTA- functionalized graphene electrode as an effective solution for the removal of Lead from water.