1
|
Wu ZF, Sun PZ, Wahab OJ, Tan YT, Barry D, Periyanagounder D, Pillai PB, Dai Q, Xiong WQ, Vega LF, Lulla K, Yuan SJ, Nair RR, Daviddi E, Unwin PR, Geim AK, Lozada-Hidalgo M. Proton and molecular permeation through the basal plane of monolayer graphene oxide. Nat Commun 2023; 14:7756. [PMID: 38012200 PMCID: PMC10682477 DOI: 10.1038/s41467-023-43637-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 11/15/2023] [Indexed: 11/29/2023] Open
Abstract
Two-dimensional (2D) materials offer a prospect of membranes that combine negligible gas permeability with high proton conductivity and could outperform the existing proton exchange membranes used in various applications including fuel cells. Graphene oxide (GO), a well-known 2D material, facilitates rapid proton transport along its basal plane but proton conductivity across it remains unknown. It is also often presumed that individual GO monolayers contain a large density of nanoscale pinholes that lead to considerable gas leakage across the GO basal plane. Here we show that relatively large, micrometer-scale areas of monolayer GO are impermeable to gases, including helium, while exhibiting proton conductivity through the basal plane which is nearly two orders of magnitude higher than that of graphene. These findings provide insights into the key properties of GO and demonstrate that chemical functionalization of 2D crystals can be utilized to enhance their proton transparency without compromising gas impermeability.
Collapse
Affiliation(s)
- Z F Wu
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
| | - P Z Sun
- Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau, 999078, China.
| | - O J Wahab
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Y T Tan
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - D Barry
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
| | - D Periyanagounder
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
| | - P B Pillai
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
- Department of Chemical Engineering, The University of Manchester, Manchester, M13 9PL, UK
| | - Q Dai
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
| | - W Q Xiong
- Key Laboratory of Artificial Micro- and Nano-structures of the Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - L F Vega
- Research and Innovation Center on CO2 and Hydrogen (RICH Center) and Chemical Engineering Department, Khalifa University, PO Box 127788, Abu Dhabi, United Arab Emirates
- Research and Innovation Center for graphene and 2D materials (RIC2D), Khalifa University, PO Box 127788, Abu Dhabi, United Arab Emirates
| | - K Lulla
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
| | - S J Yuan
- Key Laboratory of Artificial Micro- and Nano-structures of the Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China
| | - R R Nair
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK
- Department of Chemical Engineering, The University of Manchester, Manchester, M13 9PL, UK
| | - E Daviddi
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - P R Unwin
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom.
| | - A K Geim
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK.
| | - M Lozada-Hidalgo
- Department of Physics and Astronomy, The University of Manchester, Manchester, M13 9PL, UK.
- National Graphene Institute, The University of Manchester, Manchester, M13 9PL, UK.
- Research and Innovation Center for graphene and 2D materials (RIC2D), Khalifa University, PO Box 127788, Abu Dhabi, United Arab Emirates.
| |
Collapse
|
2
|
Wahab OJ, Daviddi E, Xin B, Sun PZ, Griffin E, Colburn AW, Barry D, Yagmurcukardes M, Peeters FM, Geim AK, Lozada-Hidalgo M, Unwin PR. Proton transport through nanoscale corrugations in two-dimensional crystals. Nature 2023; 620:782-786. [PMID: 37612394 PMCID: PMC10447238 DOI: 10.1038/s41586-023-06247-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 05/23/2023] [Indexed: 08/25/2023]
Abstract
Defect-free graphene is impermeable to all atoms1-5 and ions6,7 under ambient conditions. Experiments that can resolve gas flows of a few atoms per hour through micrometre-sized membranes found that monocrystalline graphene is completely impermeable to helium, the smallest atom2,5. Such membranes were also shown to be impermeable to all ions, including the smallest one, lithium6,7. By contrast, graphene was reported to be highly permeable to protons, nuclei of hydrogen atoms8,9. There is no consensus, however, either on the mechanism behind the unexpectedly high proton permeability10-14 or even on whether it requires defects in graphene's crystal lattice6,8,15-17. Here, using high-resolution scanning electrochemical cell microscopy, we show that, although proton permeation through mechanically exfoliated monolayers of graphene and hexagonal boron nitride cannot be attributed to any structural defects, nanoscale non-flatness of two-dimensional membranes greatly facilitates proton transport. The spatial distribution of proton currents visualized by scanning electrochemical cell microscopy reveals marked inhomogeneities that are strongly correlated with nanoscale wrinkles and other features where strain is accumulated. Our results highlight nanoscale morphology as an important parameter enabling proton transport through two-dimensional crystals, mostly considered and modelled as flat, and indicate that strain and curvature can be used as additional degrees of freedom to control the proton permeability of two-dimensional materials.
Collapse
Affiliation(s)
- O J Wahab
- Department of Chemistry, University of Warwick, Coventry, UK
| | - E Daviddi
- Department of Chemistry, University of Warwick, Coventry, UK
| | - B Xin
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK
- National Graphene Institute, The University of Manchester, Manchester, UK
| | - P Z Sun
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK
- National Graphene Institute, The University of Manchester, Manchester, UK
| | - E Griffin
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK
- National Graphene Institute, The University of Manchester, Manchester, UK
| | - A W Colburn
- Department of Chemistry, University of Warwick, Coventry, UK
| | - D Barry
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - M Yagmurcukardes
- Department of Photonics, Izmir Institute of Technology, Urla, Turkey
| | - F M Peeters
- Departement Fysica, Universiteit Antwerpen, Antwerp, Belgium
- Departamento de Fisica, Universidade Federal do Ceara, Fortaleza, Brazil
| | - A K Geim
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK.
- National Graphene Institute, The University of Manchester, Manchester, UK.
| | - M Lozada-Hidalgo
- Department of Physics and Astronomy, The University of Manchester, Manchester, UK.
- National Graphene Institute, The University of Manchester, Manchester, UK.
| | - P R Unwin
- Department of Chemistry, University of Warwick, Coventry, UK.
| |
Collapse
|