Surface and interfacial interactions of multilayer graphitic structures with local environment

THIN SOLID FILMS

卷:585

Article

Mazzocco, R.¹  Robinson, B. J.¹  Rabot, C.²  Delamoreanu, A.³  Zenasni, A.²  Dickinson, J. W.⁴  Boxall, C.⁴  Kolosov, O. V.¹ 

[1] Univ Lancaster, Dept Phys, Lancaster LA1 4YB, England

[2] CEA Grenoble, LETI, F-38054 Grenoble 09, France

[3] Univ Grenoble 1, French Natl Res Ctr, CNRS, Microelect Technol Lab LTM, F-38054 Grenoble 9, France

[4] Univ Lancaster, Dept Engn, Lancaster LA1 4YR, England

关键词: Graphene;    Thickness measurement;    Segregation;    Chemical reduction;    Atomic force microscopy;    Ultrasonic force microscopy;   

DOI  :  10.1016/j.tsf.2015.04.016

来源: Elsevier

【 摘 要 】

In order to exploit the potential of graphene in next-generation devices, such as supercapacitors, rechargeable batteries, displays and ultrathin sensors, it is crucial to understand the solvent interactions with the graphene surface and interlayers, especially where the latter may be in competition with the former, in the medium of application deployment. In this report, we combine quartz crystal microbalance (QCM) and ultrasonic force microscopy methods to investigate the changes in the film-substrate and film-environment interfaces of graphene and graphene oxide films, produced by diverse scalable routes, in both polar (deionised water) and non-polar (dodecane) liquid and vapour environments. In polar liquid environments, we observe nanobubble adsorption/desorption on the graphene film corresponding to a surface coverage of up to 20%. As no comparable behaviour is observed for non-polar environment, we conclude that nanobubble formation is directly due to the hydrophobic nature of graphene with direct consequences for electrode structures immersed in electrolyte solutions. The amount of water adsorbed by the graphene films was found to vary considerably from 0.012 monolayers of water per monolayer of reduced graphene oxide to 0.231 monolayers of water per monolayer of carbon diffusion growth graphene. This is supported by direct nanomechanical mapping of the films immersed in water where an increased variation of local stiffness suggests water propagation within the film and/or between the film and substrate. Transferred film thickness calculations performed for QCM, atomic force microscopy topography and optical transmission measurements, returns results an order of magnitude larger (46 +/- 1 layers) than Raman spectroscopy (1 - 2 graphene layers) on pristine pre-transferred films due to contamination during transfer and possible turbostratic structures of large areas. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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