Solid-state semiconductor gas sensors have been attracting a great deal of attention for over two decades, due to their importance in gas analysis and safety applications. The chemical sensitivity of a semiconductor surface serves as a way to transduce the chemical information about the surfaces into an electrical signal for gas-sensing applications.
Sensor technology development has a long history [1]. It includes thick-film and thin-film technology, and, recently, semiconductor nanotechnology. Size-dependent physical properties are very important in the theory and construction of sensor devices, and metal and semiconductor nanoparticles are basic components of older and even recently used gas-sensitive materials.
This Special Issue of Nanomaterials will attempt to show some items from the gas sensor technology, and nano-sized structures for gas sensor applications.
The first article (Orientation Ordering and Chiral Superstructures in Fullerene Monolayer on Cd (0001)) [2] is not strongly related to the gas sensor subject. However, the fullerene thin film interaction with the Cd surface has been investigated by STM, including spectroscopy for the HOMO-LUMO energy gap. The virtuous use of experimental techniques resulted in high-quality images of Cd-Fullerene structures. The results are of great importance to the carbon-based nanotechnology, nano-devices, and nanomaterials.
All other articles [3,4,5,6,7,8] are related to different nanostructured semiconductor gas sensor materials for numerous gases (see lists below) with different types of sensor constructions, such as the surface acoustic wave substrate, Taguchi type (ceramic tube substrate with heater inside), or just simple heated insulator plate substrate (oxidized silicon, or others, for example Al2O3).
| Material | Technology | Gas Sensitivity |
| mesoporous AlO(OH) | sol-gel and spin-coating | NH3 |
| SnO2–NiO nanoneedles | hydrothermal synthesis | NO2 |
| α-Fe2O3 nanoparticles | in situ corrosion method of scorodite | xylene |
| NiO-ZnO nanorods | hydrothermal/sol-gel | H2S |
| WO3–SnO2 composite nanorod | hydrothermal/sputtering | acetone |
| SnO2, Pd/SnO2, Au/SnO2, AuPd/SnO2 nanocomposites | flame spray pyrolysis | C3H8, CO, CH4, H2, NO2, NH3, acetone. |
Articles [3,4,5,6,7,8] detail the experimental technique, analytical methods, measurement methods, and results in sufficient depth. Developments are successful concerning sensor properties: all gas sensors produced significant selectivity and sensitivity to the given gases.
Generally, it can be concluded that nanotechnology adds some extra possibilities to conventional technologies and materials; see more in [9].
Funding
This research received no external funding.
Conflicts of Interest
The authors declare no conflict of interest.
References
- Mizsei, J. Forty years of adventure with semiconductor gas sensors. Procedia Eng. 2016, 168, 221–226. [Google Scholar] [CrossRef] [Scilit]
- Shang, Y.; Wang, Z.; Yang, D.; Wang, Y.; Ma, C.; Tao, M.; Sun, K.; Yang, J.; Wang, J. Orientation Ordering and Chiral Superstructures in Fullerene Monolayer on Cd (0001). Nanomaterials 2020, 10, 1305. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Liang, Y.C.; Chao, Y. Enhancement of Acetone Gas-Sensing Responses of Tapered WO3 Nanorods through Sputtering Coating with a Thin SnO2 Coverage Layer. Nanomaterials 2019, 9, 864. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Ao, D.; Li, Z.; Fu, Y.; Tang, Y.; Yan, S.; Zu, X. Heterostructured NiO/ZnO Nanorod Arrays with Significantly Enhanced H2S Sensing Performance. Nanomaterials 2019, 9, 900. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Wang, Y.; Tang, X.; Cao, S.; Chen, X.; Rong, Z. The Synthesis of the Pomegranate-Shaped α-Fe2O3 Using an In Situ Corrosion Method of Scorodite and Its Gas-Sensitive Property. Nanomaterials 2019, 9, 977. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Wei, Z.; Zhou, Q.; Wang, J.; Lu, Z.; Xu, L.; Zeng, W. Hydrothermal Synthesis of SnO2 Nanoneedle-Anchored NiO Microsphere and its Gas Sensing Performances. Nanomaterials 2019, 9, 1015. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Xu, X.; Zu, X.; Ao, D.; Yu, J.; Xiang, X.; Xie, W.; Tang, Y.; Li, S.; Fu, Y. NH3-Sensing Mechanism Using Surface Acoustic Wave Sensor with AlO(OH) Film. Nanomaterials 2019, 9, 1732. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Krivetskiy, V.; Zamanskiy, K.; Beltyukov, A.; Asachenko, A.; Topchiy, M.; Nechaev, M.; Garshev, A.; Krotova, A.; Filatova, D.; Maslakov, K.; et al. Effect of AuPd Bimetal Sensitization on Gas Sensing Performance of Nanocrystalline SnO2 Obtained by Single Step Flame Spray Pyrolysis. Nanomaterials 2019, 9, 728. [Google Scholar] [CrossRef] [Scilit] [PubMed]
- Hunter, G.W.; Akbar, S.; Bhansali, S.; Daniele, M.; Erb, P.D.; Johnson, K.; Liu, C.-C.; Miller, D.; Oralkan, O.; Hesketh, P.J. Editors’ Choice—Critical Review—A Critical Review of Solid State Gas Sensors. J. Electrochem. Soc. 2020, 167, 037570. [Google Scholar] [CrossRef] [Scilit]
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |
© 2022 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).