Critical temperatures in the synthesis of graphene-like materials by thermal exfoliation-reduction of graphite oxide
[EN] We prepared a series of graphene-like materials by thermal exfoliation/reduction of a graphite oxide (GO) at temperatures between 127 °C and 2400 °C. The extent of the exfoliation and reduction of the GO at different temperatures, as well as the impact on the resultant graphene-like materials (...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2013 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/87966 |
| Acceso en línea: | http://hdl.handle.net/10261/87966 |
| Access Level: | acceso abierto |
| Palabra clave: | Graphene Graphite oxide Graphene materials Thermal exfoliation |
| Sumario: | [EN] We prepared a series of graphene-like materials by thermal exfoliation/reduction of a graphite oxide (GO) at temperatures between 127 °C and 2400 °C. The extent of the exfoliation and reduction of the GO at different temperatures, as well as the impact on the resultant graphene-like materials (TRGs), were studied through their chemical/structural characterization. The main oxygen loss was observed at 127 °C during the blasting of the GO, which produced its exfoliation into monolayer functionalized TRG with hydroxyl groups and minor amounts of epoxy and carboxyl groups. Above 600 °C, the reduction continued smoothly, with oxygen and hydrogen loss and the conversion of hybridised carbon atoms from sp3 into sp2. 1000 °C appears to be a critical temperature for the efficiency of the reduction process, as the resulting TRG contained <2% oxygen and 81.5% sp2-carbon atoms. The materials obtained at 2000 °C and 2400 °C were almost oxygen-free and the layers exhibited a dramatic restoration of the pristine graphite structure, as confirmed by the increase in the average size of the sp2-domains. The typical disordered stacking of TRGs increases with temperature, although they can be dispersed yielding monolayers at 127 and 300 °C and stacks of up to 4–6 layers above 1000 °C, as determined by AFM. |
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