1
|
Wang J, Yu H, Zhou X, Liu X, Zhang R, Lu Z, Zheng J, Gu L, Liu K, Wang D, Jiao L. Probing the crystallographic orientation of two-dimensional atomic crystals with supramolecular self-assembly. Nat Commun 2017; 8:377. [PMID: 28851863 PMCID: PMC5575328 DOI: 10.1038/s41467-017-00329-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 06/22/2017] [Indexed: 11/10/2022] Open
Abstract
Probing the crystallographic orientation of two-dimensional (2D) materials is essential to understand and engineer their properties. However, the nondestructive identification of the lattice orientations of various 2D materials remains a challenge due to their very thin nature. Here, we identify the crystallographic structures of various 2D atomic crystals using molecules as probes by utilizing orientation-dependent molecule–substrate interactions. We discover that the periodic atomic packing of 2D materials guides oleamide molecules to assemble into quasi-one-dimensional nanoribbons with specific alignments which precisely indicate the lattice orientations of the underlying materials. Using oleamide molecules as probes, we successfully identify the crystallographic orientations of ~12 different 2D materials without degrading their intrinsic properties. Our findings allow for the nondestructive identification of the lattice structure of various 2D atomic crystals and shed light on the functionalization of these 2D materials with supramolecular assembly. Identifying the crystallographic orientations of 2D materials is important, but methods to do so are typically destructive. Here, the authors show that the orientational dependency of self-assembled nanoribbons of oleamide molecules can be used to non-invasively probe the lattice orientations of various 2D substrates.
Collapse
Affiliation(s)
- Jinghui Wang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Hongde Yu
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Xu Zhou
- State Key Laboratory for Mesoscopic Physics, Collaborative Innovation Center of Quantum Matter, School of Physics, Academy for Advanced Interdisciplinary Studies, Center for Nanochemisty, Peking University, Beijing, 100871, China
| | - Xiaozhi Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Renjie Zhang
- Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education, Shandong University, Jinan, 250100, China
| | - Zhixing Lu
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Jingying Zheng
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Lin Gu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Kaihui Liu
- State Key Laboratory for Mesoscopic Physics, Collaborative Innovation Center of Quantum Matter, School of Physics, Academy for Advanced Interdisciplinary Studies, Center for Nanochemisty, Peking University, Beijing, 100871, China
| | - Dong Wang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China.
| | - Liying Jiao
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China.
| |
Collapse
|
3
|
Casford MTL, Davies PB. The structure of oleamide films at the aluminum/oil interface and aluminum/air interface studied by Sum Frequency Generation (SFG) vibrational spectroscopy and Reflection Absorption Infrared Spectroscopy (RAIRS). ACS APPLIED MATERIALS & INTERFACES 2009; 1:1672-1681. [PMID: 20355782 DOI: 10.1021/am900199f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The structure of oleamide (cis-9-octadecenamide) films on aluminum has been investigated by sum frequency generation vibrational spectroscopy (SFG) and reflection absorption infrared spectroscopy (RAIRS). Three different film deposition strategies were investigated: (i) films formed by equilibrium adsorption from oleamide solutions in oil, (ii) Langmuir-Blodgett films cast at 1 and 25 mN m(-1), (iii) thick spin-cast films. Both L-B and spin-cast films were examined in air and under oil. The adsorbate formed in the 1 mN m(-1) film in air showed little orientational order. For this film, the spectroscopic results and the ellipsometric thickness point to a relatively conformationally disordered monolayer that is oriented principally in the plane of the interface. Direct adsorption to the metal interface from oil results in SFG spectra of oleamide that are comparable to those observed for the 1 mN m(-1) L-B film in air. In contrast, SFG and RAIRS results for the 25 mN m(-1) film in air and SFG spectra of the spin-cast film in air both show strong conformational ordering and orientational alignment normal to the interface. The 25 mN m(-1) film has an ellipsometric thickness almost twice that of the 1 mN m(-1) L-B film. Taken in combination with the spectroscopic results, this is indicative of a well packed monolayer in air in which the hydrocarbon chain is in an essentially defect-free extended conformation with the methyl terminus oriented away from the surface. A similar structure is also deduced for the surface of the spin-cast film in air. Upon immersion of the 25 mN m(-1) L-B film in oil the SFG spectra show that this film rapidly adopts a relatively disordered structure similar to that seen for the 1 mN m(-1) L-B film in air. Immersion of the spin-cast film in oil results in the gradual disordering of the amide film over a period of several days until the observed spectra become essentially identical to those observed for direct adsorption of oleamide from oil.
Collapse
Affiliation(s)
- Michael T L Casford
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
| | | |
Collapse
|