Measuring the proton selectivity of graphene membranes
- Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)
By systematically studying the proton selectivity of free-standing graphene membranes in aqueous solutions, we demonstrate that protons are transported by passing through defects. We study the current-voltage characteristics of single-layer graphene grown by chemical vapour deposition (CVD) when a concentration gradient of HCl exists across it. Our measurements can unambiguously determine that H{sup +} ions are responsible for the selective part of the ionic current. By comparing the observed reversal potentials with positive and negative controls, we demonstrate that the as-grown graphene is only weakly selective for protons. We use atomic layer deposition to block most of the defects in our CVD graphene. Our results show that a reduction in defect size decreases the ionic current but increases proton selectivity.
- OSTI ID:
- 22486132
- Journal Information:
- Applied Physics Letters, Vol. 107, Issue 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
Similar Records
Deconstructing proton transport through atomically thin monolayer CVD graphene membranes
Assessing the quality of large-area monolayer graphene grown on liquid copper for size-selective ionic/molecular membrane separations