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Titel
Temperature dependence of the electrical conductivity of activated carbons prepared from vine shoots by physical and chemical activation methods
Autor(es)
Schlagwort
Vine shoots
Activated carbon
Electrical conductivity
Energy gap
Clasificación UNESCO
2303 Química Inorgánica
3321.02 Productos Químicos derivados del Carbón
Fecha de publicación
2015
Verlag
Elsevier
Citación
Barroso-Bogeat, A., Alexandre-Franco, M., Fernández-González, C., Macías-García, A., Gómez-Serrano, V. (2015). Temperature dependence of dc electrical conductivity of activated carbons prepared from vine shoots by physical and chemical activation methods, Microporous and Mesoporous Materials, 209. pp 90-98. http://dx.doi.org/10.1016/j.micromeso.2014.07.023
Resumen
[EN] A broadly varied series of activated carbons (ACs) was prepared from vine shoots (VS) by the method of
physical activation in air, CO2 and steam, and by the method of chemical activation with H3PO4, ZnCl2 and
KOH aqueous solutions. Here, the temperature dependence of the dc electrical conductivity for the ACs is
studied from room temperature up to 200ºC. The bulk electrical conductivity of the carbon samples is
found to be the result of a complex interplay between several factors, texture and surface chemistry likely
being the most relevant ones. The best conductivity values are obtained for sample carbonized at 900ºC.
The physical activation stage has been proved to decrease the conductivity of the carbonized products,
the reduction being more pronounced for air than for CO2 and steam. Such a detrimental effect of physical
activation on conductivity has been associated with the formation of oxygen groups and structures on
carbon surface rather than with the porosity development. The conductivity of ACs prepared by chemical
activation is even lower than for physically activated samples, likely due to the higher degree of porosity
development. All carbon samples, irrespective of the activation method and activating agent, behave as
semiconductor materials and therefore the electrical conduction is related to an energy gap (Eg). The
Eg values widely vary from 0.084 eV for the sample carbonized at 900ºC up to 0.659 eV for the AC
prepared by physical activation in air.
URI
ISSN
1387-1811
DOI
10.1016/j.micromeso.2014.07.023
Versión del editor
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