Crystalline hydrogenation of graphene by scanning tunneling microscope tip-induced field dissociation of H2. (November 2017)

• Record Type: Journal Article
• Authors: Tjung, S.J.; Hollen, S.M.; Gambrel, G.A.; Santagata, N.M.; Johnston-Halperin, E.; Gupta, J.A.
• Is Part Of: Carbon. Volume 124(2017)
• Page Start: 97
• Page End: 104
• Publication Date: 2017-11
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2017.07.044
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: We have developed a novel method for crystalline hydrogenation of graphene on the nanoscale. Molecular hydrogen was physisorbed at 5 K onto pristine graphene islands grown on Cu(111) in ultrahigh vacuum. Field emission local to the tip of a scanning tunneling microscope dissociates H2 and results in hydrogenated graphene. At lower coverage, isolated point defects are found on the graphene and are attributed to chemisorbed H on top and bottom surfaces. Repeated H2 exposure and field emission yielded patches and then complete coverage of a crystalline √3 × √3 R30° phase, as well as less densely packed 3 × 3 and 4 × 4 structures. The hydrogenation can be reversed by imaging with higher bias voltage. Graphical abstract: