An electroactive ion exchange hybrid film with collaboratively-driven ability for electrochemically-mediated selective extraction of chloride ions

The development of selective separation materials with large capacity and high selectivity has always been a research hotspot in the field of water remediation. In this study, an electroactive ion exchange hybrid film of bismuth oxychloride/chloride ion-imprinted polypyrrole (BiOCl/PPy-Cl) with core-shell nanosheet structure was successfully fabricated by a chemical oxidation method for selective extraction of chloride ions. Herein, the BiOCl/PPy-Cl hybrid film possessed superior conductivity due to the incorporation of the conductive polymer. Furthermore, the hybrid film could more quickly and effectively extract Cl- compared with BiOCl and PPy-Cl, and its uptake capacity reached as high as 80.81 mg.g(-1) at the optimal potential of 0.6 V. Meanwhile, based on the screening effect brought by the outer PPy-Cl shell, the hybrid film displayed prominent selectivity toward Cl- even in the presence of other competing species. In addition, the hybrid film maintained steady adsorption capacity in 10 cycles as well as under different acid-base environments. The outstanding Cl- uptake performance of the hybrid film was primarily ascribed to the open interlayer structure of BiOCl and the collaboratively-driven force generated by the reversible electrochemical redox of BiOCl and PPy. It is expected that the obtained BiOCl/PPy-Cl hybrid film could be a promising alternative for the extraction of Cl- from wastewater.

Automated summary

In this study, a BiOCl/PPy-Cl hybrid film with core-shell nanosheet structure was successfully fabricated for selective extraction of chloride ions with superior conductivity and high adsorption capacity. The hybrid film displayed prominent selectivity and stable adsorption performance towards Cl- due to the outer PPy-Cl shell. The excellent Cl- uptake performance was attributed to the open interlayer structure of BiOCl and the collaboratively-driven force generated by the reversible electrochemical redox of BiOCl and PPy.