Graphene growth from reduced graphene oxide by chemical vapour deposition: seeded growth accompanied by restoration

Sung-Jin Chang, Moon Seop Hyun, Sung Myung, Min-A Kang, Jung Ho Yoo, Kyoung G. Lee, Bong Gill Choi, Youngji Cho, Gaehang Lee, Tae Jung Park
2016 Scientific Reports  
Understanding the underlying mechanisms involved in graphene growth via chemical vapour deposition (CVD) is critical for precise control of the characteristics of graphene. Despite much effort, the actual processes behind graphene synthesis still remain to be elucidated in a large number of aspects. Herein, we report the evolution of graphene properties during in-plane growth of graphene from reduced graphene oxide (RGO) on copper (Cu) via methane CVD. While graphene is laterally grown from RGO
more » ... flakes on Cu foils up to a few hundred nanometres during CVD process, it shows appreciable improvement in structural quality. The monotonous enhancement of the structural quality of the graphene with increasing length of the graphene growth from RGO suggests that seeded CVD growth of graphene from RGO on Cu surface is accompanied by the restoration of graphitic structure. The finding provides insight into graphene growth and defect reconstruction useful for the production of tailored carbon nanostructures with required properties. The growth of graphene on copper (Cu) substrates via chemical vapour deposition (CVD) 1,2 has been extensively exploited for the purpose of achieving large-area, high-quality single crystals, which are highly desirable for the practical use of graphene in industrial applications 3-6 . Together with their technological appeal, such systems also serve as a unique platform for broadening our fundamental understanding of a new and intriguing class of growth phenomena. In particular, the overall properties of CVD-grown graphene films are sensitively dependent on diverse parameters 7-12 including purity of copper, types of carbon precursors, temperature, and vapour pressure. However, the wide variation in properties of CVD-grown graphene films under similar growth conditions suggests that fine-tuning of the growth parameters is still required. Thus, the actual processes and the underlying mechanisms involved in graphene growth 7-15 are vital to understand for achieving precise control of the graphene growth. CVD growth of graphene on Cu is a surface-mediated process 14 . During the CVD process, nucleation of graphene critical nuclei occurs spontaneously and randomly on the Cu surface, and then monolayer graphene is subsequently synthesized from the edge of the graphene nuclei [13] [14] [15] [16] . Recently, monolayer graphene has been also grown from seeds intentionally patterned or prepared on Cu prior to the CVD process 16-19 , instead of from graphene seeds spontaneously and randomly nucleated on Cu during the CVD process. Specifically, CVD-grown graphene monolayer or multilayer grains 17,18 and mechanically exfoliated graphene or graphite flakes 17,18 have been utilized as seeds for obtaining high-quality monolayer graphene. In addition, poly(methyl methacrylate) (PMMA) dots 19 and chemically derived graphene oxide (GO) flakes 20 have been also used for seeded CVD
doi:10.1038/srep22653 pmid:26961409 pmcid:PMC4785362 fatcat:slxjpqhyyrcytgjlkdfa656rhe