Revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single-walled carbon nanotubes
A catalyst is essential for the controlled synthesis of single-walled carbon nanotubes (SWNTs) by chemical vapour deposition (CVD). However, it is difficult to observe these nanosized particles in their original forms and in a statistical manner, which has resulted in a vague understanding of the be...
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| Format: | Article |
| Language: | English |
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The Royal Society
2018-01-01
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| Series: | Royal Society Open Science |
| Subjects: | |
| Online Access: | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.180345 |
| _version_ | 1818480436089716736 |
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| author | Rong Xiang Shigeo Maruyama |
| author_facet | Rong Xiang Shigeo Maruyama |
| author_sort | Rong Xiang |
| collection | DOAJ |
| description | A catalyst is essential for the controlled synthesis of single-walled carbon nanotubes (SWNTs) by chemical vapour deposition (CVD). However, it is difficult to observe these nanosized particles in their original forms and in a statistical manner, which has resulted in a vague understanding of the behaviours of these particles. We present a technique to solve this long-standing issue. The key is to have an MEMS fabricated suspended SiO2 layer, which is thick enough to support catalyst deposition and nanotube growth but thin enough to allow electron beams to transit. On a 20 nm SiO2 film, we confirm that catalyst can be observed at an atomic resolution, and the catalyst–SWNT junctions can also be routinely observed. As a demonstration of this technique, we revisited the behaviour of monometallic catalysts through a systematic investigation of the size, chemical state and crystal structure of particles before and after high-temperature CVD. The active catalyst is found to follow a tangential growth mode, while the inactive catalyst is divided into three mechanisms: size growth, metal loss and inappropriate precipitation. The latter two mechanisms were not possible to observe by previous techniques. |
| first_indexed | 2024-12-10T11:23:34Z |
| format | Article |
| id | doaj.art-c51ef82dae1f4fdd97f928ea5380e1b7 |
| institution | Directory Open Access Journal |
| issn | 2054-5703 |
| language | English |
| last_indexed | 2024-12-10T11:23:34Z |
| publishDate | 2018-01-01 |
| publisher | The Royal Society |
| record_format | Article |
| series | Royal Society Open Science |
| spelling | doaj.art-c51ef82dae1f4fdd97f928ea5380e1b72022-12-22T01:50:50ZengThe Royal SocietyRoyal Society Open Science2054-57032018-01-015810.1098/rsos.180345180345Revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single-walled carbon nanotubesRong XiangShigeo MaruyamaA catalyst is essential for the controlled synthesis of single-walled carbon nanotubes (SWNTs) by chemical vapour deposition (CVD). However, it is difficult to observe these nanosized particles in their original forms and in a statistical manner, which has resulted in a vague understanding of the behaviours of these particles. We present a technique to solve this long-standing issue. The key is to have an MEMS fabricated suspended SiO2 layer, which is thick enough to support catalyst deposition and nanotube growth but thin enough to allow electron beams to transit. On a 20 nm SiO2 film, we confirm that catalyst can be observed at an atomic resolution, and the catalyst–SWNT junctions can also be routinely observed. As a demonstration of this technique, we revisited the behaviour of monometallic catalysts through a systematic investigation of the size, chemical state and crystal structure of particles before and after high-temperature CVD. The active catalyst is found to follow a tangential growth mode, while the inactive catalyst is divided into three mechanisms: size growth, metal loss and inappropriate precipitation. The latter two mechanisms were not possible to observe by previous techniques.https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.180345single-walled carbon nanotubecatalysttransmission electron microscopy |
| spellingShingle | Rong Xiang Shigeo Maruyama Revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single-walled carbon nanotubes Royal Society Open Science single-walled carbon nanotube catalyst transmission electron microscopy |
| title | Revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single-walled carbon nanotubes |
| title_full | Revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single-walled carbon nanotubes |
| title_fullStr | Revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single-walled carbon nanotubes |
| title_full_unstemmed | Revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single-walled carbon nanotubes |
| title_short | Revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single-walled carbon nanotubes |
| title_sort | revisiting behaviour of monometallic catalysts in chemical vapour deposition synthesis of single walled carbon nanotubes |
| topic | single-walled carbon nanotube catalyst transmission electron microscopy |
| url | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.180345 |
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