U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Main content area

An electroactive montmorillonite/polypyrrole ion exchange film: Ultrahigh uptake capacity and ion selectivity for rapid removal of lead ions

Yaqin Rong, Wenjun Yan, Zhongde Wang, Xiaogang Hao, Guoqing Guan
Journal of hazardous materials 2022 v.437 pp. 129366
adsorbents, adsorption, aquatic organisms, electrostatic interactions, heavy metals, humans, ion exchange, lead, montmorillonite, nanocomposites, nanosheets, pyrroles
Contact with trace heavy metal contaminants will also lead to extremely bad health influence on human body and aquatic life. Although various adsorbents have been synthesized for the recovery of heavy metal ions, most of them shows deficient adsorption capacity, sluggish uptake rate and low selectivity. In this study, a montmorillonite/polypyrrole (MMT/PPy) film was successfully synthesized by intercalating polymers PPy into the interlayer of MMT nanosheets for selective and rapid capture of Pb²⁺. The electroactive film has ultrahigh uptake capacity (1373.29 mg⋅g⁻¹), which is much higher than most conventional Pb²⁺ adsorbents. Meanwhile, it had an extreme selectivity towards Pb²⁺ due to the MMT/PPy film can accurately identified Pb²⁺. Through characterization testing and data analysis, the selective and rapid uptake/release of Pb²⁺ should be realized through three ways: (1) negatively-charged laminates of MMT can generate electrostatic attraction to Pb²⁺; (2) -OH on the surface of MMT laminates can accurately identified and bonded with Pb²⁺ (M-O-H↔ M-O-Pb); (3) PPy doped by PSSⁿ⁻ and protic acid can rapidly catch Pb²⁺ (PPy⁺·PSSⁿ⁻+Pb²⁺+e⁻→ PPy·PSSⁿ⁻·Pb²⁺). Therefore, such a novel MMT/PPy nanocomposite film could has evident application prospect to remove Pb²⁺ from various water bodies.