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. 2022 Apr 27;14(9):1780.
doi: 10.3390/polym14091780.

Preparation and Characterization of PEDOT:PSS/TiO2 Micro/Nanofiber-Based Gas Sensors

Bing-Chiuan Shiu  1   2 , Yan-Ling Liu  3 , Qian-Yu Yuan  3 , Ching-Wen Lou  2   3   4   5   6 , Jia-Horng Lin  1   2   5   7   8
Affiliations

Preparation and Characterization of PEDOT:PSS/TiO2 Micro/Nanofiber-Based Gas Sensors

Bing-Chiuan Shiu et al. Polymers (Basel). .

Abstract

In this study, we employed electrospinning technology and in situ polymerization to prepare wearable and highly sensitive PVP/PEDOT:PSS/TiO2 micro/nanofiber gas sensors. PEDOT, PEDOT:PSS, and TiO2 were prepared via in situ polymerization and tested for characteristic peaks using energy-dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FT-IR), then characterized using a scanning electron microscope (SEM), a four-point probe resistance measurement, and a gas sensor test system. The gas sensitivity was 3.46-12.06% when ethanol with a concentration between 12.5 ppm and 6250 ppm was measured; 625 ppm of ethanol was used in the gas sensitivity measurements for the PEDOT/composite conductive woven fabrics, PVP/PEDOT:PSS nanofiber membranes, and PVP/PEDOT:PSS/TiO2 micro/nanofiber gas sensors. The latter exhibited the highest gas sensitivity, which was 5.52% and 2.35% greater than that of the PEDOT/composite conductive woven fabrics and PVP/PEDOT:PSS nanofiber membranes, respectively. In addition, the influence of relative humidity on the performance of the PVP/PEDOT:PSS/TiO2 micro/nanofiber gas sensors was examined. The electrical sensitivity decreased with a decrease in ethanol concentration. The gas sensitivity exhibited a linear relationship with relative humidity lower than 75%; however, when the relative humidity was higher than 75%, the gas sensitivity showed a highly non-linear correlation. The test results indicated that the PVP/PEDOT:PSS/TiO2 micro/nanofiber gas sensors were flexible and highly sensitive to gas, qualifying them for use as a wearable gas sensor platform at room temperature. The proposed gas sensors demonstrated vital functions and an innovative design for the development of a smart wearable device.

Keywords: gas sensitivity; gas-sensitive nanofiber; micro/nanofiber gas sensor; smart wearable device.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
PVP/PEDOT:PSS/TiO2 micro/nanofiber gas sensor structure.
Figure 2
Figure 2
(a) Image of gas sensor and (b) schematic diagram of test circuit.
Figure 3
Figure 3
Surface morphology of (a,b) PEDOT/composite conductive woven fabric and (c) Cu/Pc-80 conductive woven fabric.
Figure 4
Figure 4
FT−IR spectra of (a) Cu/Pc−80 conductive woven fabrics and (b) PEDOT/composite conductive woven fabrics.
Figure 5
Figure 5
Response curve of PEDOT/composite woven fabrics in relation to ethanol concentration.
Figure 6
Figure 6
Morphology and structure of the nanofibers of (a–c) pure PVP membranes and (a’–c’) PEDOT:PSS nanofiber membranes with a PVP content of 8, 9, and 10%. Morphology of (d) pure PVP/TiO2 membranes and (d’) PVP/PEDOT:PSS/TiO2 membranes at a specified PVP content of 9%.
Figure 7
Figure 7
EDS analysis of (a) PVP/PEDOT:PSS and (b) PVP/PEDOT:PSS/TiO2 nanofiber membranes.
Figure 8
Figure 8
XRD patterns of (a) pure TiO2 powder and (b) PVP/TiO2 nanofiber membranes.
Figure 9
Figure 9
FT-IR diagram of (a) PEDOT:PSS solution, (b) pure PVP nanofiber membranes, (c) PVP/PEDOT:PSS nanofiber membranes, and (d) PVP/PEDOT:PSS/TiO2 nanofiber membranes.
Figure 10
Figure 10
(a) The response curve of PVP/PEDOT:PSS/TiO2 micro/nanofiber gas sensors exposed to different concentrations of ethanol (62.5 ppm-6250 ppm). (b) Comparative response curve of different sensors with a specified ethanol concentration of 625 ppm.
Figure 11
Figure 11
The influence of relative humidity (11–86%) on the gas sensitivity response of the sensors.
See this image and copyright information in PMC

References

    1. Heeger A.J. Semiconducting and metallic polymers: The fourth generation of polymeric materials (Nobel lecture) Angew. Chem. Int. Ed. 2001;40:2591–2611. doi: 10.1002/1521-3773(20010716)40:14<2591::AID-ANIE2591>3.0.CO;2-0. - DOI - PubMed
    1. Winter I., Reese C., Hormes J., Heywang G., Jonas F. The thermal ageing of poly (3, 4-ethylenedioxythiophene). An investigation by X-ray absorption and X-ray photoelectron spectroscopy. Chem. Phys. 1995;194:207–213. doi: 10.1016/0301-0104(95)00026-K. - DOI
    1. Groenendaal L., Jonas F., Freitag D., Pielartzik H., Reynolds J.R. Poly (3, 4-ethylenedioxythiophene) and its derivatives: Past, present, and future. Adv. Mater. 2000;12:481–494. doi: 10.1002/(SICI)1521-4095(200004)12:7<481::AID-ADMA481>3.0.CO;2-C. - DOI
    1. Wang Y., Jia W., Strout T., Ding Y., Lei Y. Preparation, characterization and sensitive gas sensing of conductive core-sheath TiO2-PEDOT nanocables. Sensors. 2009;9:6752–6763. doi: 10.3390/s90906752. - DOI - PMC - PubMed
    1. Hidayat S.N., Julian T., Rianjanu A., Kusumaatmadja A., Triyana K. Quartz crystal microbalance coated by PAN nanofibers and PEDOT: PSS for humidity sensor; Proceedings of the 2017 International Seminar on Sensors, Instrumentation, Measurement and Metrology (ISSIMM); Surabaya, Indonesia. 25–26 August 2017; pp. 119–123.

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