Tunable semi-permeability of graphene-based membranes by adjusting reduction degree of laminar graphene oxide layer

• Published in: Journal of membrane science Vol. 547; pp. 73 - 79
• Main Authors: Yang, Euntae, Ham, Moon-Ho, Park, Ho Bum, Kim, Chang-Min, Song, Jun-ho, Kim, In S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2018
• Subjects: Graphene oxide; Ion rejection; Nanochannel; Reduction degree; Nanochannel; Reduction degree; Graphene oxide; Ion rejection
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2017.10.039

Membrane-based water reuse and desalination technologies have been increasingly popular as an alternative water resource for mitigating global water scarcity. However, intrinsic limitations of conventional membranes restrict a further advance in membrane-based technologies. Recently, laminar-structure graphene oxide (GO) membranes fabricated by staking GO nanoplatelets have been emerging as a new water purification membrane with overcoming the conventional membrane limitations because of ultra-fast water permeation and precise molecular sieving capability based on ultra-low friction and well-defined nanochannels; to apply laminar GO membranes for ion removal such as desalination, tuning size of GO nanochannels within a sub-nanometer range is required. Herein, we adjusted reduction degree of GO laminates via varying exposure time to hydroiodic acid steam to control the size of GO nanochannels in a sub-nanometer range. Control of the hydroiodic acid vapor exposure time is a facile way to tune the nanochannel size in a sub-nanometer, and consequentially monovalent ion rejection rate can be handled. [Display omitted] •Graphene oxide (GO) laminates was exposed to hydroiodic acid (HI) vapor for reduction.•Exposure time to HI vapor was controlled to adjust degree of reduction of GO laminates.•With increasing degree of reduction of GO layer, the GO nanochannel size was decreased.•Water/ion semipermeability can be controlled by manipulating degree of reduction of GO layer.