Photocatalytic and Gas Sensitive Multiwalled Carbon Nanotube/TiO<sub>2</sub>-ZnO and ZnO-TiO<sub>2</sub> Composites Prepared by Atomic Layer Deposition
TiO<sub>2</sub> and ZnO single and multilayers were deposited on hydroxyl functionalized multi-walled carbon nanotubes using atomic layer deposition. The bare carbon nanotubes and the resulting heterostructures were characterized by TG/DTA, Raman, XRD, SEM-EDX, XPS, TEM-EELS-SAED and low...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-01-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/10/2/252 |
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| author | László Péter Bakos Nóra Justh Ulisses Carlo Moura da Silva Bezerra da Costa Krisztina László János László Lábár Tamás Igricz Katalin Varga-Josepovits Pawel Pasierb Elina Färm Mikko Ritala Markku Leskelä Imre Miklós Szilágyi |
| author_facet | László Péter Bakos Nóra Justh Ulisses Carlo Moura da Silva Bezerra da Costa Krisztina László János László Lábár Tamás Igricz Katalin Varga-Josepovits Pawel Pasierb Elina Färm Mikko Ritala Markku Leskelä Imre Miklós Szilágyi |
| author_sort | László Péter Bakos |
| collection | DOAJ |
| description | TiO<sub>2</sub> and ZnO single and multilayers were deposited on hydroxyl functionalized multi-walled carbon nanotubes using atomic layer deposition. The bare carbon nanotubes and the resulting heterostructures were characterized by TG/DTA, Raman, XRD, SEM-EDX, XPS, TEM-EELS-SAED and low temperature nitrogen adsorption techniques, and their photocatalytic and gas sensing activities were also studied. The carbon nanotubes (CNTs) were uniformly covered with anatase TiO<sub>2</sub> and wurtzite ZnO layers and with their combinations. In the photocatalytic degradation of methyl orange, the most beneficial structures are those where ZnO is the external layer, both in the case of single and double oxide layer covered CNTs (CNT-ZnO and CNT-TiO<sub>2</sub>-ZnO). The samples with multilayer oxides (CNT-ZnO-TiO<sub>2</sub> and CNT-TiO<sub>2</sub>-ZnO) have lower catalytic activity due to their larger average densities, and consequently lower surface areas, compared to single oxide layer coated CNTs (CNT-ZnO and CNT-TiO<sub>2</sub>). In contrast, in gas sensing it is advantageous to have TiO<sub>2</sub> as the outer layer. Since ZnO has higher conductivity, its gas sensing signals are lower when reacting with NH<sub>3</sub> gas. The double oxide layer samples have higher resistivity, and hence a larger gas sensing response than their single oxide layer counterparts. |
| first_indexed | 2024-04-12T00:20:47Z |
| format | Article |
| id | doaj.art-fdfe6986600b42a5a8a33795ce99aa6a |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-04-12T00:20:47Z |
| publishDate | 2020-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-fdfe6986600b42a5a8a33795ce99aa6a2022-12-22T03:55:44ZengMDPI AGNanomaterials2079-49912020-01-0110225210.3390/nano10020252nano10020252Photocatalytic and Gas Sensitive Multiwalled Carbon Nanotube/TiO<sub>2</sub>-ZnO and ZnO-TiO<sub>2</sub> Composites Prepared by Atomic Layer DepositionLászló Péter Bakos0Nóra Justh1Ulisses Carlo Moura da Silva Bezerra da Costa2Krisztina László3János László Lábár4Tamás Igricz5Katalin Varga-Josepovits6Pawel Pasierb7Elina Färm8Mikko Ritala9Markku Leskelä10Imre Miklós Szilágyi11Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4., H-1111 Budapest, HungaryDepartment of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4., H-1111 Budapest, HungaryDepartment of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4., H-1111 Budapest, HungaryDepartment of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, P.O. Box 92, H-1521 Budapest, HungaryInstitute for Technical Physics and Materials Science, Research Centre of Energy, Hungarian Academy of Sciences, Konkoly–Thege út 29–33., H-1121 Budapest, HungaryDepartment of Organic Chemistry and Technology, Budapest University of Technology and Economics, Budafoki út 8., H-1111 Budapest, HungaryDepartment of Atomic Physics, Budapest University of Technology and Economics, Budafoki út 8., H-1111 Budapest, HungaryDepartment of Inorganic Chemistry, AGH University of Science and Technology, Mickiewicza 30., 30-059 Kraków, PolandASM Microchemistry Oy, Pietari Kalmin katu 1F2, FI-00560 Helsinki, FinlandDepartment of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, FinlandDepartment of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, FinlandDepartment of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szent Gellért tér 4., H-1111 Budapest, HungaryTiO<sub>2</sub> and ZnO single and multilayers were deposited on hydroxyl functionalized multi-walled carbon nanotubes using atomic layer deposition. The bare carbon nanotubes and the resulting heterostructures were characterized by TG/DTA, Raman, XRD, SEM-EDX, XPS, TEM-EELS-SAED and low temperature nitrogen adsorption techniques, and their photocatalytic and gas sensing activities were also studied. The carbon nanotubes (CNTs) were uniformly covered with anatase TiO<sub>2</sub> and wurtzite ZnO layers and with their combinations. In the photocatalytic degradation of methyl orange, the most beneficial structures are those where ZnO is the external layer, both in the case of single and double oxide layer covered CNTs (CNT-ZnO and CNT-TiO<sub>2</sub>-ZnO). The samples with multilayer oxides (CNT-ZnO-TiO<sub>2</sub> and CNT-TiO<sub>2</sub>-ZnO) have lower catalytic activity due to their larger average densities, and consequently lower surface areas, compared to single oxide layer coated CNTs (CNT-ZnO and CNT-TiO<sub>2</sub>). In contrast, in gas sensing it is advantageous to have TiO<sub>2</sub> as the outer layer. Since ZnO has higher conductivity, its gas sensing signals are lower when reacting with NH<sub>3</sub> gas. The double oxide layer samples have higher resistivity, and hence a larger gas sensing response than their single oxide layer counterparts.https://www.mdpi.com/2079-4991/10/2/252carbon nanotubestitanium dioxidezinc oxideatomic layer depositionphotocatalysisgas sensing |
| spellingShingle | László Péter Bakos Nóra Justh Ulisses Carlo Moura da Silva Bezerra da Costa Krisztina László János László Lábár Tamás Igricz Katalin Varga-Josepovits Pawel Pasierb Elina Färm Mikko Ritala Markku Leskelä Imre Miklós Szilágyi Photocatalytic and Gas Sensitive Multiwalled Carbon Nanotube/TiO<sub>2</sub>-ZnO and ZnO-TiO<sub>2</sub> Composites Prepared by Atomic Layer Deposition Nanomaterials carbon nanotubes titanium dioxide zinc oxide atomic layer deposition photocatalysis gas sensing |
| title | Photocatalytic and Gas Sensitive Multiwalled Carbon Nanotube/TiO<sub>2</sub>-ZnO and ZnO-TiO<sub>2</sub> Composites Prepared by Atomic Layer Deposition |
| title_full | Photocatalytic and Gas Sensitive Multiwalled Carbon Nanotube/TiO<sub>2</sub>-ZnO and ZnO-TiO<sub>2</sub> Composites Prepared by Atomic Layer Deposition |
| title_fullStr | Photocatalytic and Gas Sensitive Multiwalled Carbon Nanotube/TiO<sub>2</sub>-ZnO and ZnO-TiO<sub>2</sub> Composites Prepared by Atomic Layer Deposition |
| title_full_unstemmed | Photocatalytic and Gas Sensitive Multiwalled Carbon Nanotube/TiO<sub>2</sub>-ZnO and ZnO-TiO<sub>2</sub> Composites Prepared by Atomic Layer Deposition |
| title_short | Photocatalytic and Gas Sensitive Multiwalled Carbon Nanotube/TiO<sub>2</sub>-ZnO and ZnO-TiO<sub>2</sub> Composites Prepared by Atomic Layer Deposition |
| title_sort | photocatalytic and gas sensitive multiwalled carbon nanotube tio sub 2 sub zno and zno tio sub 2 sub composites prepared by atomic layer deposition |
| topic | carbon nanotubes titanium dioxide zinc oxide atomic layer deposition photocatalysis gas sensing |
| url | https://www.mdpi.com/2079-4991/10/2/252 |
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