Synthesis of Vertically-Aligned Carbon Nanotubes from Langmuir-Blodgett Films Deposited Fe Nanoparticles on Al2O3/Al/SiO2/Si Substrate
| Autor: | Shota Takagiwa, Masahito Kushida, Kentaro Nakamura, Osamu Kanasugi |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Materials science
Iron Biomedical Engineering Molecular Conformation Nanoparticle Metal Nanoparticles Bioengineering Electrolyte Carbon nanotube Langmuir–Blodgett film Catalysis law.invention law Materials Testing General Materials Science Crystallization Particle Size chemistry.chemical_classification Nanotubes Carbon General Chemistry Condensed Matter Physics Hydrocarbon Chemical engineering chemistry Particle size |
| Zdroj: | Journal of nanoscience and nanotechnology. 16(4) |
| ISSN: | 1533-4880 |
| Popis: | In order to apply vertically-aligned carbon nanotubes (VA-CNTs) to a new Pt supporting material of polymer electrolyte fuel cell (PEFC), number density and outer diameter of CNTs must be controlled independently. So, we employed Langmuir-Blodgett (LB) technique for depositing CNT growth catalysts. A Fe nanoparticle (NP) was used as a CNT growth catalyst. In this study, we tried to thicken VA-CNT carpet height and inhibit thermal aggregation of Fe NPs by using Al2O3/Al/SiO2/Si substrate. Fe NP LB films were deposited on three typed of substrates, SiO2/Si, as-deposited Al2O3/Al/SiO2/Si and annealed Al2O3/Al/SiO2/Si at 923 K in Ar atmosphere of 16 Pa. It is known that Al2O3/Al catalyzes hydrocarbon reforming, inhibits thermal aggregation of CNT growth catalysts and reduces CNT growth catalysts. It was found that annealed Al2O3/Al/SiO2/Si exerted three effects more strongly than as-deposited Al2O3/Al/SiO2/Si. VA-CNTs were synthesized from Fe NPs-C16 LB films by thermal chemical vapor deposition (CVD) method. As a result, at the distance between two nearest CNTs 28 nm or less, VA-CNT carpet height on annealed Al2O3/Al/SiO2/Si was about twice and ten times thicker than that on SiO2/Si and that on as-deposited Al2O3/Al/SiO2/Si, respectively. Moreover, distribution of CNT outer diameter on annealed Al2O3/Al/SiO2/Si was inhibited compared to that on SiO2/Si. These results suggest that since thermal aggregation of Fe NPs is inhibited, catalyst activity increases and distribution of Fe NP size is inhibited. |
| Databáze: | OpenAIRE |
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