Light-assisted recovery of reacted MoS2 for reversible NO2 sensing at room temperature

Yunsung Kang, Soonjae Pyo, Eunhwan Jo, Jongbaeg Kim

Research output: Contribution to journalArticlepeer-review

54 Scopus citations

Abstract

Two-dimensional (2D) nanomaterials have been extensively explored as promising candidates for gas sensing due to their high surface-to-volume ratio. Among many 2D nanomaterials, molybdenum disulfide (MoS2) is known to be functional in detecting harmful gases at room temperature; therefore, it has been actively studied as a gas sensing material. However, there has been a limitation in recovering the original signal from reacted MoS2 after exposure to the target gas. This work demonstrates the recovery of the initial resistance of reacted chemical vapor deposition-grown MoS2 by illuminating it with a UV light-emitting diode (LED). A novel mechanism involving photo-generated electron-hole pairs in MoS2 is proposed and experimentally verified. The fabricated sensor detects nitrogen dioxide (NO2) and distinguishes between concentrations from 1 to 10 ppm with the proposed recovery process. Reversible detection after repeated exposure to 5 ppm NO2 over eight cycles is achieved through UV-LED illumination for a short time during the recovery process, while the identical sensor without UV illumination shows a transitional response at each cycle. To apply a low cost gas sensing solution at room temperature, visible light LEDs are also used to recover the resistance of the reacted MoS2.

Original languageEnglish
Article number355504
JournalNanotechnology
Volume30
Issue number35
DOIs
StatePublished - 12 Jun 2019

Keywords

  • molybdenum disulfide
  • nitrogen dioxide sensor
  • recovery
  • room temperature gas sensor
  • UV-LED illumination

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