2024-03-28T11:47:17Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1806922019-04-30T00:58:10Zcom_10261_84com_10261_5col_10261_337
From graphene oxide to pristine graphene: revealing the inner workings of the full structural restoration
Rozada Rodríguez, Rubén
Paredes Nachón, Juan Ignacio
López, María J.
Villar Rodil, Silvia
Cabria, Iván
Alonso, Julio A.
Martínez Alonso, Amelia
Díez Tascón, Juan Manuel
Ministerio de Economía y Competitividad (España)
Villar Rodil, Silvia [0000-0002-5832-9971]
Paredes Nachón, Juan Ignacio [0000-0002-0044-9153]
Martínez Alonso, Amelia [0000-0002-7183-0859]
Díez Tascón, Juan Manuel [0000-0001-9219-7266]
High temperature annealing is the only method known to date that allows the complete repair of a defective lattice of graphenes derived from graphite oxide, but most of the relevant aspects of such restoration processes are poorly understood. Here, we investigate both experimentally (scanning probe microscopy) and theoretically (molecular dynamics simulations) the thermal evolution of individual graphene oxide sheets, which is rationalized on the basis of the generation and the dynamics of atomic vacancies in the carbon lattice. For unreduced and mildly reduced graphene oxide sheets, the amount of generated vacancies was so large that they disintegrated at 1773–2073 K. By contrast, highly reduced sheets survived annealing and their structure could be completely restored at 2073 K. For the latter, a minor atomic-sized defect with six-fold symmetry was observed and ascribed to a stable cluster of nitrogen dopants. The thermal behavior of the sheets was significantly altered when they were supported on a vacancy-decorated graphite substrate, as well as for the overlapped/stacked sheets. In these cases, a net transfer of carbon atoms between neighboring sheets via atomic vacancies takes place, affording an additional healing process. Direct evidence of sheet coalescence with the step edge of the graphite substrate was also gathered from experiments and theory.
2019-04-29T10:13:37Z
2019-04-29T10:13:37Z
2014-12-16
artículo
Nanoscale 7(6): 2374-2390 (2015)
2040-3364
http://hdl.handle.net/10261/180692
10.1039/C4NR05816J
2040-3372
http://dx.doi.org/10.13039/501100003329
eng
Postprint
https://doi.org/10.1039/C4NR05816J
Sí
https://creativecommons.org/licenses/by-nc-nd/4.0/
openAccess
Royal Society of Chemistry (UK)