Flexible and easy-handling pristine polypyrrole membranes with bayberry-like vesicle structure for enhanced Cr(VI) removal from aqueous solution

Polypyrrole has been extensively explored for Cr(VI) removal from wastewater towing to the advantages of superior performance, low cost, facile synthesis, and high environmental stability. However, the unsatisfactory adsorption capacity and complicated process of adsorbent separation from aqueous solutions remain a huge challenge, limiting its practical application. Herein, a flexible PPy membrane with bayberry-like vesicle struc-tures (PPy-B) was prepared via template-assisted interfacial polymerization. It was found that sodium sulfosa-licylate not only improved the flexibility and strength of the PPy-B membrane for easy-handling but also participated in the polymerization of PPy as a dopant to improve the specific surface area and doping level for increasing adsorption sites. Benefiting from these, the easy-handling PPy-B membrane exhibited a high adsorption capacity (586.90-682.50 mg/g at 298-318 K), a high reusability (five adsorption-desorption cycles),and a high ultimate adsorption capacity after adsorption-desorption cycles until membrane failure (1174.86 mg/ g at 298 K). The proposed mechanisms of the enhanced Cr(VI) removal involve electrostatic adsorption, reduction, and ion exchange. This flexible PPy membrane therefore shows attractive advantages in wastewater treatment.

Automated summary

In this study, a flexible polypyrrole membrane (PPy-B) with bayberry-like vesicle structures was prepared using template-assisted interfacial polymerization. Sodium sulfosalicylate was introduced as a dopant to improve the flexibility and strength of the membrane, as well as to increase the specific surface area and doping level. The PPy-B membrane exhibited high adsorption capacity, reusability, and ultimate adsorption capacity, making it a promising candidate for wastewater treatment.