Gas Sensors Based on Mechanically Exfoliated MoS2 Nanosheets for Room-Temperature NO2 Detection

Abstract

The unique properties of MoS2 nanosheets make them a promising candidate for high-performance room temperature gas detection. Herein, few-layer MoS2 nanosheets (FLMN) prepared via mechanical exfoliation are coated on a substrate with interdigital electrodes for room-temperature NO2 detection. Interestingly, compared with other NO2 gas sensors based on MoS2, FLMN gas sensors exhibit high responsivity for room-temperature NO2 detection, and NO2 is easily desorbed from the sensor surface with an ultrafast recovery behavior, with recovery times around 2 s. The high responsivity is related to the fact that the adsorbed NO2 can affect the electron states within the entire material, which is attributed to the very small thickness of the MoS2 nanosheets. First-principles calculations were carried out based on the density functional theory (DFT) to verify that the ultrafast recovery behavior arises from the weak van der Waals binding between NO2 and the MoS2 surface. Our work suggests that FLMN prepared via mechanical exfoliation have a great potential for fabricating high-performance NO2 gas sensors.

Controlled synthesis of ultrathin MoS2nanoflowers for highly enhanced NO2sensing at room temperature

“…17,37 However, some other works indicated that in spite of slow rates of gas adsorption and desorption, the pristine MoS 2 -based sensors showed the complete recovery at RT to target gases. 20,[38][39][40] This characteristic can be attributed to several factors, such as high specic surface area, defective/strained surface and weak van der Waals binding between the target gas and the MoS 2 surface. 20,38,39 In addition, Ikram et al indicated that the high specic surface area not only increases the response of the sensor but also plays an important role in fast response and recovery times.…”

Strategy and Future Prospects to Develop Room-Temperature-Recoverable NO2 Gas Sensor Based on Two-Dimensional Molybdenum Disulfide

“… Pt/Ti Resistor 0.5 200 11 33 107 [ 24 ] MoS 2 Nanosheets p M.E. Ag/Pd Resistor 100 RT 29 42 2 [ 309 ] MoS 2 -W n Hyd. Ag/Pd Resistor 20 RT 171 41 39 [ 121 ] MoS 2 -Au p S.P.…”

Recent Progress in the Synthesis of MoS2 Thin Films for Sensing, Photovoltaic and Plasmonic Applications: A Review

“…Similarly (Figure 9b), DFT calculations indicated that the fairly fast recovery of MoS2 arises from the weak van der Waals interactions between NO2 and the MoS2 surface. Furthermore, exfoliated few-layer MoS 2 nanosheets deposited on a substrate with interdigitated electrodes demonstrated good NO 2 detection performances at room temperature [168]. The reported device shows a quick and complete recovery time of 2 s at a rate greater than 97%.…”

“…Due to the strong response and excellent signal-to-noise ratio, a detection limit of TEA as low as 10 ppb was achieved. Furthermore, exfoliated few-layer MoS2 nanosheets deposited on a substrate with interdigitated electrodes demonstrated good NO2 detection performances at room temperature [168]. The reported device shows a quick and complete recovery time of 2s at a rate greater than 97%.…”