title: Self-Assembly: A Facile Way of Forming Ultrathin, High-Performance Graphene Oxide Membranes for Water Purification.
abstract: Single-layer graphene oxide (SLGO) is emerging as a new-generation membrane material for high-flux, high-selectivity water purification, owing to its favorable two-dimensional morphology that allows facile fabrication of ultrathin membranes with subnanometer interlayer channels. However, reliable and precise molecular sieving performance still necessarily depends on thick graphene oxide (GO) deposition that usually leads to low water flux. This trade-off between selectivity and flux significantly impedes the development of ultrathin GO membranes. In this work, we demonstrate that the selectivity/flux trade-off can be broken by self-assembly of SLGO via simple deposition rate control. We find GO membranes, prepared by slow deposition of SLGO flakes, exhibit considerably improved salt rejection, while counterintuitively having 2.5-4 times higher water flux than that of membranes prepared by fast deposition. This finding has extensive implications of designing/tuning interlayer nanostructure of ultrathin GO membranes by simply controlling SLGO deposition rate and thus may greatly facilitate their development for high flux, high selectivity water purification.
authors.affiliation: Department of Chemical Engineering and Catalysis for Renewable Fuels Center, University of South Carolina , Columbia, South Carolina 29208, United States.
authors.forename: Weiwei L
authors.identifier: 0000-0001-7671-4753
authors.initials: WL
authors.lastname: Xu
authors.affiliation: Department of Mechanical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Chao
authors.initials: C
authors.lastname: Fang
authors.affiliation: Department of Chemical Engineering and Catalysis for Renewable Fuels Center, University of South Carolina , Columbia, South Carolina 29208, United States.
authors.forename: Fanglei
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Department of Chemical Engineering and Catalysis for Renewable Fuels Center, University of South Carolina , Columbia, South Carolina 29208, United States.
authors.forename: Zhuonan
authors.initials: Z
authors.lastname: Song
authors.affiliation: Department of Chemical Engineering and Catalysis for Renewable Fuels Center, University of South Carolina , Columbia, South Carolina 29208, United States.
authors.forename: Qiuli
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Rui
authors.identifier: 0000-0001-5219-5530
authors.initials: R
authors.lastname: Qiao
authors.affiliation: Department of Chemical Engineering and Catalysis for Renewable Fuels Center, University of South Carolina , Columbia, South Carolina 29208, United States.
authors.forename: Miao
authors.initials: M
authors.lastname: Yu
keywords: Graphene oxide; interlayer nanostructure; membrane; self-assembly; water purification