Sensitive NO2 sensor based on silver nanowires-decorated monolayer graphene with assistance of UV illumination

Defect-Driven MoS2 Nanosheets toward Enhanced Sensing Sensitivity

“…29 Taking this into account, proton irradiation was conducted on the exfoliated MoS 2 with different densities of 10 11 , 10 12 , 10 13 , and 10 14 ions/cm 2 , along with nonirradiated MoS 2 for comparison. The MoS 2 materials were denoted as i10 11 , i10 12 , i10 13 , and i10 14 , respectively.…”

“…As shown in Figure , it can be observed that the resistance of MoS 2 nanosheets increased for all of the materials upon NO 2 exposure. NO 2 gas molecules are known for their electron-withdrawing characteristics due to the existence of a lone electron on the N atom. , Therefore, NO 2 molecules adsorbed on the MoS 2 surface cause a depletion of electrons in MoS 2 , resulting in a decrease in the conductance or an increase in the resistance. These results provided solid evidence of the n-type behavior of MoS 2 because p-type MoS 2 materials induce resistance changes in the opposite direction, decreasing resistance, upon exposure to electron acceptors like NO 2 gas.…”

“…9 For example, MoS 2 flakes were successfully incorporated into field-effect transistorbased gas sensors for detecting NO 2 10 and NH 3 . 11 The sensing sensitivity of the MoS 2 -based sensor can be considered comparable to that of other nanomaterials such as graphene, 12,13 nanoparticles, 14 and nanocomposites. 15−17 To enhance sensing sensitivity, chemical-vapor-deposition-grown MoS 2 was employed.…”

“…For example, MoS 2 flakes were successfully incorporated into field-effect transistor-based gas sensors for detecting NO 2 and NH 3 . The sensing sensitivity of the MoS 2 -based sensor can be considered comparable to that of other nanomaterials such as graphene, , nanoparticles, and nanocomposites. − To enhance sensing sensitivity, chemical-vapor-deposition-grown MoS 2 was employed . Instead of MoS 2 flakes, the monolayer of MoS 2 exhibited outstanding sensitivity with a detection limit as low as 20 ppb for NO 2 and 1 ppm for NH 3 at room temperature.…”