A novel potential oscillation in situ removal method: preparation of ion imprinted 8-HQ/PPy film for the selective separation of zinc ions

The zinc ion-imprinted 8-hydroxyquinoline/polypyrrole (8-HQ/PPy) composite film is successfully prepared by using the unipolar pulse electropolymerization (UPEP) method on the carbon cloth substrate. Based on the electrochemically switched ion exchange (ESIX) method, the ion-imprinted film is used to selectively separate zinc ions in the aqueous solution. The zinc ion adsorption kinetics is studied in a batch experiment due to the specific recognition of the ion-imprinted composite film toward zinc ion. The kinetics data of zinc ion adsorption by the imprinted composite film fits well with the pseudo-first-order kinetic model. As a result, when the adsorption potential and initial concentration are - 1.2 V and 25 ppm, respectively, the ion exchange capacity of the imprinted composite film for zinc ions reaches 145.6 mg g(-1). In addition, the separation factor (alpha) are 2.6 and 2.3 of the imprinted composite film for Zn2+ compared with Co2+ and Ni2+, which is attributed to the specific recognition ability of the imprinted composite film for zinc ions. It is expected that the imprinted composite film prepared by the described method can be used for the separation target metal ions.