Selective reduction of epoxy groups in graphene oxide membrane for ultrahigh water permeation. (February 2021)

• Record Type: Journal Article
• Authors: Yi, Ruobing; Xia, Xinming; Yang, Rujie; Yu, Risheng; Dai, Fangfang; Chen, Junlang; Liu, Wei; Wu, Minghong; Xu, Jing; Chen, Liang
• Is Part Of: Carbon. Volume 172(2021)
• Page Start: 228
• Page End: 235
• Publication Date: 2021-02
• Subjects: Graphene oxide membrane -- Selective reduction -- Oxygen-containing groups -- Water permeation; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2020.09.076
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Permeation of graphene oxide (GO) membranes is expected to improve significantly when epoxy groups are removed while retaining hydroxyl groups in the GO flakes. However, it is still difficult for conventional reduction methods to achieve such selective reduction of oxygen-containing groups. In this paper, we demonstrated the precise selective reduction of GO flakes with low epoxy content but high hydroxyl content using modified electron beam irradiation (EBI). Remarkably, membranes prepared with the reduced GO flakes (EBI-rGO) have ultrahigh water permeation from 92.7 to 267.1 L m −2 h −1 bar −1 while still maintaining the effective rejection rates for both dyes (methyl blue, pararosaniline and rhodamine B) and multivalent metal ions (Fe 3+, Pb 2+ and Cu 2+ ). Theoretical calculations show that newly generated hydroxyl, obtained by reducing epoxy using the hydrogen radical (H), plays an important role in controlling selective reduction. Our study provides an effective way to fabricate GO membranes with outstanding water purification performance. Graphical abstract: Electron beam irradiation (EBI) reduction can reduce most of epoxy groups and maintain the hydroxyl content achieving the purpose of selective reduction of GO. Image 1