Extraction of Sr2+ from aqueous solutions using an asymmetric pulsed current-assisted electrochemical method

In this paper, 4′-aminobenzo-18-crown-6 ether was grafted onto the surface of carbon felt via a diazotization reaction, and a composite material ([email protected]) was obtained. Then, [email protected] was used as an electrode to extract Sr2+ from aqueous solutions and simulated seawater by an asymmetric pulsed current-assisted electrochemical (AP-CE) method. Due to the excellent conductivity of carbon felt and the selectivity of crown ether molecules, the [email protected] electrode exhibited excellent electrochemical extraction performance. Under the optimal alternating potential, the maximum removal efficiency and maximum adsorption capacity of Sr2+ reached 99.5% and 668.9 mg g−1, respectively. The Sr2+ ions adsorbed on the surface of the [email protected] electrode could be desorbed by applying a positive voltage without an eluent, and the [email protected] electrode displayed good recyclability. This work provides an effective strategy for developing covalently-decorated crown ether carbon felt electrodes. The AP-CE method is of great significance for the selective electrosorption of metal ions.