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Response of Palladium and Carbon Nanotube Composite Films to Hydrogen Gas and Behavior of Conductive Carriers
To develop a high-performance hydrogen gas sensor, we fabricated a composite film made of carbon nanotubes (CNTs) and palladium nanoparticles. Carbon nanotubes were spin-coated onto a glass substrate, and subsequently, palladium nanoparticles were sputtered onto this film. The response to hydrogen g...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7602456/ https://www.ncbi.nlm.nih.gov/pubmed/33066660 http://dx.doi.org/10.3390/ma13204568 |
Sumario: | To develop a high-performance hydrogen gas sensor, we fabricated a composite film made of carbon nanotubes (CNTs) and palladium nanoparticles. Carbon nanotubes were spin-coated onto a glass substrate, and subsequently, palladium nanoparticles were sputtered onto this film. The response to hydrogen gas was measured during two seasons (summer and winter) using a vacuum chamber by introducing a hydrogen/argon gas mixture. There was a clear difference in the sensor response despite the temperature difference between summer and winter. In addition, since a clean chamber was used, fewer water molecules acted as a dopant, and the behavior of the CNT changed from p-type to n-type because of the dissociative adsorption of hydrogen. This phenomenon was confirmed as the Seebeck effect. Finally, the work functions of Pd, PdH(x), and CNT were calculated by first-principle calculations. As predicted by previous studies, a decrease in work function due to hydrogen adsorption was confirmed; however, the electron transfer to CNT was not appropriate from the perspective of charge neutrality and was found to be localized at the Pd/CNT interface. It seems that the Seebeck effect causes the concentration of conductive carriers to change. |
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