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. 2021 Dec 13;11(12):3377.
doi: 10.3390/nano11123377.

AZO-Based ZnO Nanosheet MEMS Sensor with Different Al Concentrations for Enhanced H2S Gas Sensing

Yempati Nagarjuna  1 , Jun-Cong Lin  1 , Sheng-Chang Wang  1 , Wen-Tse Hsiao  2 , Yu-Jen Hsiao  1
Affiliations

AZO-Based ZnO Nanosheet MEMS Sensor with Different Al Concentrations for Enhanced H2S Gas Sensing

Yempati Nagarjuna et al. Nanomaterials (Basel). .

Abstract

The properties of H2S gas sensing were investigated using a ZnO nanostructure prepared with AZO (zinc oxide with aluminium) and Al surfaces which were developed on a MEMS (Micro Electromechanical System) device. Hydrothermal synthesis was implemented for the deposition of the ZnO nanostructure. To find the optimal conditions for H2S gas sensing, different ZnO growth times and different temperatures were considered and tested, and the results were analysed. At 250 °C and 90 min growth time, a ZnO sensor prepared with AZO and 40 nm Al recorded an 8.5% H2S gas-sensing response at a 200 ppb gas concentration and a 14% sensing response at a gas concentration of 1000 ppb. The dominant sensing response provided the optimal conditions for the ZnO sensor, which were 250 °C temperature and 90 min growth time. Gas sensor selectivity was tested with five different gases (CO, SO2, NO2, NH3 and H2S) and the sensor showed great selectivity towards H2S gas.

Keywords: AZO; H2S gas sensing; MEMS device; ZnO nanostructure; gas selectivity.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
(a–h): Fabrication process of the MEMS microheater device.
Figure 2
Figure 2
Three-dimensional figure of the fabricated MEMS microheater.
Figure 3
Figure 3
XRD image of ZnO nanosheets at different growth times.
Figure 4
Figure 4
SEM images of (a) pure AZO, (b) AZO with 10 nm of Al, (c) AZO with 20 nm of Al, (d) AZO with 40 nm of Al, (e) AZO with 80 nm of Al.
Figure 5
Figure 5
Comparison of ZnO nanostructure prepared on 40 nm Al AZO with different growth times: (a) 45 min, (b) 90 min, (c) 180 min, (d) 270 min.
Figure 6
Figure 6
Comparison of ZnO nanostructure cross-sectional SEM images prepared on 40 nm Al AZO under different growth times (a) 45 min (b) 90 min (c) 180 min (d) 270 min.
Figure 7
Figure 7
EDS spectrum analysis of (a) Pure AZO, (b) AZO with 10 nm of Al, (c) AZO with 20 nm of Al, (d) AZO with 40 nm of Al, (e) AZO with 80 nm of Al.
Figure 8
Figure 8
Power vs. Temperature graph of the MEMS microheater.
Figure 9
Figure 9
H2S gas-sensing response of ZnO nanostructure prepared with 45 min growth time: (a) at 150 °C, (b) 200 °C, (c) 250 °C, (d) 300 °C.
Figure 10
Figure 10
H2S gas-sensing response of ZnO nanostructure prepared with 90 min growth time: (a) at 150 °C, (b) 200 °C, (c) 250 °C, (d) 300 °C.
Figure 11
Figure 11
H2S gas-sensing response of the ZnO nanostructure prepared with 180 min growth time: (a) at 150 °C, (b) 200 °C, (c) 250 °C, (d) 300 °C.
Figure 12
Figure 12
Summary of the H2S gas-sensing responses of ZnO nanostructure prepared on AZO and 40 nm Al at different temperatures with growth times of (a) 45 min, (b) 90 min, (c) 180 min, (d) 270 min.
Figure 13
Figure 13
(a) Repeatability gas-sensing test; (b) selectivity of ZnO sensor for different target gases.
Figure 14
Figure 14
Gas-sensing mechanism of ZnO sensor with H2S gas.
See this image and copyright information in PMC

References

    1. Du F., Guo Z., Cheng Z., Kremer M., Shuang S., Liu Y., Dong C. Facile synthesis of ultrahigh fluorescent N, S-self-doped carbon nanodots and their multiple applications for H2S sensor, bioimaging in live cells and zebrafish, and anti-counterfeiting. Nanoscale. 2020;12:20482–20490. doi: 10.1039/D0NR04649C. - DOI - PubMed
    1. Muthusamy S., Kanagaraj R., Zhu D., Zhao L., Wang S., Zhu W. A novel lysosome targeted fluorophore for H2S sensing: Enhancing the quantitative detection with successive reaction sites. Sens. Actuators B Chem. 2020;320:128433. doi: 10.1016/j.snb.2020.128433. - DOI
    1. Myadam N.L., Nadargi D.Y., Nadargi J.D., Kudkyal V.R., Shaikh F.I., Mulla I.S., Suryavanshi S.S., Chaskar M.G. Ni/SnO2 xerogels via epoxide chemistry: Potential candidate for H2S gas sensing application. J. Porous Mater. 2020;28:239–248. doi: 10.1007/s10934-020-00970-5. - DOI
    1. Ding P., Xu D., Dong N., Chen Y., Xu P., Zheng D., Li X. A high-sensitivity H2S gas sensor based on optimized ZnO-ZnS nano-heterojunction sensing material. Chin. Chem. Lett. 2020;31:2050–2054. doi: 10.1016/j.cclet.2019.11.024. - DOI
    1. Tang Y., Wu W., Wang B., Dai X., Xie W., Yang Y., Zhang R., Shi X., Zhu H., Luo J., et al. H2S gas sensing performance and mechanisms using CuO-Al2O3 composite films based on both surface acoustic wave and chemiresistor techniques. Sens. Actuators B Chem. 2020;325:128742. doi: 10.1016/j.snb.2020.128742. - DOI

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