Polyethylenimine functionalized and scaffolded graphene aerogel and the application in the highly selective separation of thorium from rare earth. (1st January 2021)

• Record Type: Journal Article
• Authors: Bai, Ruixi; Yang, Fan; Meng, Lingyi; Zhao, Zhigang; Guo, Wanghuan; Cai, Chunqing; Zhang, Yang
• Is Part Of: Materials & design. Volume 197(2021)
• Publication Date: 2021-01-01
• Subjects: Aerogel -- 3D-porous structure -- Surface modification -- Cross-linking -- High selectivity -- DFT simulation; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2020.109195
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: A polyethylenimine (PEI)-scaffolded and functionalized graphene aerogel, PEI-GO-AG, was prepared and utilized as a highly selective adsorbent for the extraction of thorium (Th) (IV) from three lanthanides (Ln) (III) elements. The three dimensional (3D)-porous structure of the adsorbent was established by the cross-linking effect of PEI via a one-step hydrothermal strategy and preserved by a freeze-drying treatment to avoid the collapse of the structure. The extractive efficiency of PEI-GO-AG displayed a sensitive dependence on the beginning mass ratio of PEI/graphene oxide (GO) in the hydrothermal step because of its significant influence on the hydrophilicity and the amounts of introduced binding sites of the adsorbent.. Besides, a density function theory (DFT)-based theoretical calculation was performed, confirming the higher stability of Th (IV)-PEI-GO-AG than that of Ln (III)-PEI-GO-AG. Ascribed to these contributions, the as-prepared adsorbent showed high selectivity towards Th (IV) among three Ln (III) elements. The separation factor ( SF ) values of Th (IV) to lanthanum (La) (III), europium (Eu) (III), and lutetium (Lu) (III) were SF Th/La = 114.41, SF Th/Eu = 52.75, and SF Th/Lu = 107.81, respectively. Abstract : Graphical abstract Unlabelled Image Highlights: 1Dimensional-porous graphene oxide aerogel was established using polyethylenimine as the cross-linking and functionalizing agent. The adsorbent possesses high selectivity arising from the dimensional-porous structure, the introduced binding sites, and the high hydrophilicity. The adsorptive performance of the adsorbent showed a sensitively dependent relationship on the beginning mass ratio of polyethylenimine/graphene oxide. A density functional theory simulation was performed, proving the adsorption complex of thorium possessed the lowest energy.