▎ 摘　　要

Reduced graphene oxide (rGO) membranes have been intensively evaluated for desalination and ionic sieving applications, benefiting from their stable and well-confined interlayer channels. However, rGO membranes generally suffer from low permeability due to the high transport resistance resulting from the narrowed two-dimensional (2D) channels. Although high permeability can be realized by reducing membrane thickness, membrane selectivity normally declines because of the formation of non-selective defects, in particular pinholes. In this study, we demonstrate that the non-selective defects in ultrathin rGO membranes can be effectively minimised by a facile posttreatment via surface-deposition of graphene quantum dots (GQDs). The resultant GQDs/rGO membranes obtained a good trade-off between water permeance (14 L.m(2).h(-1)center dot MPa-1) and NaCl rejection (91%). This work provides new insights into the design of high quality ultrathin 2D laminar membranes for desalination, molecular/ionic sieving and other separation applications. (C) 2021 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.