A Comparative Study on P-type Nickel Oxide and N-type Zinc Oxide for Gas Sensor Applications
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University of Toledo / OhioLINK
2018
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| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=toledo1525473245395728 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-toledo15254732453957282021-08-03T07:06:47Z A Comparative Study on P-type Nickel Oxide and N-type Zinc Oxide for Gas Sensor Applications Pant, Bharat Raj Mechanical Engineering Materials Science Nanoscience Nanotechnology Nickel oxide Zinc oxide gas sensor humidity sensor thin films graphene graphene oxide aluminum doping composite films The development of effective gas sensors for the detection of hazardous gases is important because of elevated concentrations of hazardous gases in the ambient. Gas sensors can be fabricated using different electronic materials such as metal oxides, carbon nanotubes, organic compounds, and ceramic compounds. Among them, metal oxides are considered as the potential materials for gas sensor application because of their high stability, high sensitivity, and ability to detect a wide range of target gases. There are some limitations associated with metal-oxide gas sensors such as low response, low conductivity, high operating temperature, and slow recovery speed. However, these limitations can be eliminated by the modification of metal oxides with impurity doping, mixing with other metal oxides, surface modification with catalytic metals. In this study, possible improvement of gas sensors by doping of impurities and addition of graphene to enhance carrier transport phenomena was investigated. Graphene was mixed with nickel oxide to produce composite films that can be used in gas sensor filament. The sensing characteristics of graphene added nickel oxide were studied as a function of graphene concentration. The samples were tested for NH3, CH4, and H2 at different operating temperatures. The response time, recovery time, cross-sensitivity, selectivity and repeatability of the test specimens were studied in details. It was found that the response, response time, recovery time, and conductivity of the films were improved after mixing of nickel oxide with graphene. The electrical properties, optical properties, and the crystal structures of the samples were studied with UV spectrophotometry and X-ray diffraction measurements. Also, zinc oxide was doped with aluminum and graphene oxide and deposited using the sol-gel method. The samples were tested for some gases and humidity. The ZnO films doped with graphene oxide and aluminum showed a better response to gases and humidity than pure ZnO films. Also, the response of the films coated on the silicon substrates was higher than the films coated on glass substrates for gases and humidity. In addition, the conductivity of the Al-doped ZnO film was higher than pure ZnO film, and the Al-doped ZnO film was able to detect humidity at room temperature. All the sensors exhibited a good selectivity and repeatability with a negligible cross sensitivity. The gas sensing performance of the NiO films was enhanced by the addition of graphene. The response of NiO and ZnO films was significantly increased when coated on the silicon substrates. After doping with Al, ZnO exhibited an improved sensitivity for humidity at room temperature. The results indicated that the gas sensing properties of metal oxides can be tuned by the addition of graphene into metal oxide films. 2018-12-21 English text University of Toledo / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=toledo1525473245395728 http://rave.ohiolink.edu/etdc/view?acc_num=toledo1525473245395728 unrestricted This thesis or dissertation is protected by copyright: some rights reserved. It is licensed for use under a Creative Commons license. Specific terms and permissions are available from this document's record in the OhioLINK ETD Center. |
| collection |
NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Mechanical Engineering Materials Science Nanoscience Nanotechnology Nickel oxide Zinc oxide gas sensor humidity sensor thin films graphene graphene oxide aluminum doping composite films |
| spellingShingle |
Mechanical Engineering Materials Science Nanoscience Nanotechnology Nickel oxide Zinc oxide gas sensor humidity sensor thin films graphene graphene oxide aluminum doping composite films Pant, Bharat Raj A Comparative Study on P-type Nickel Oxide and N-type Zinc Oxide for Gas Sensor Applications |
| author |
Pant, Bharat Raj |
| author_facet |
Pant, Bharat Raj |
| author_sort |
Pant, Bharat Raj |
| title |
A Comparative Study on P-type Nickel Oxide and N-type Zinc Oxide for Gas Sensor Applications |
| title_short |
A Comparative Study on P-type Nickel Oxide and N-type Zinc Oxide for Gas Sensor Applications |
| title_full |
A Comparative Study on P-type Nickel Oxide and N-type Zinc Oxide for Gas Sensor Applications |
| title_fullStr |
A Comparative Study on P-type Nickel Oxide and N-type Zinc Oxide for Gas Sensor Applications |
| title_full_unstemmed |
A Comparative Study on P-type Nickel Oxide and N-type Zinc Oxide for Gas Sensor Applications |
| title_sort |
comparative study on p-type nickel oxide and n-type zinc oxide for gas sensor applications |
| publisher |
University of Toledo / OhioLINK |
| publishDate |
2018 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=toledo1525473245395728 |
| work_keys_str_mv |
AT pantbharatraj acomparativestudyonptypenickeloxideandntypezincoxideforgassensorapplications AT pantbharatraj comparativestudyonptypenickeloxideandntypezincoxideforgassensorapplications |
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1719454105388187648 |