2024-03-28T21:32:06Zhttps://uvadoc.uva.es/oai/requestoai:uvadoc.uva.es:10324/324502022-06-28T11:33:42Zcom_10324_1159com_10324_931com_10324_894col_10324_1310
From graphene oxide to pristine graphene: revealing the inner workings of the full structural restoration
Rozada, Rubén
López Santodomingo, María José
Villar Rodil, Silvia
Cabria Álvaro, Iván
Alonso Martín, Julio Alfonso
Martínez Alonso, Amelia
Tascón, Juan M. D.
Producción Científica
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.
2018-11-06T07:53:49Z
2018-11-06T07:53:49Z
2015
info:eu-repo/semantics/article
Nanoscale, 2015, 7, 2374
2040-3364
http://uvadoc.uva.es/handle/10324/32450
http://dx.doi.org/10.1039/C4NR05816J
eng
https://pubs.rsc.org/en/content/articlelanding/2015/nr/c4nr05816j#!divAbstract
info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-nd/4.0/
Attribution-NonCommercial-NoDerivatives 4.0 International
Royal Society of Chemistry
SI