Table 3.

Ammonia gas sensing TMDC materials and their performances.

Material	Target Gas	LOD	Condition	Remarks
MoSe2 [149]	NH3	50 ppm	RT	Response time of 2.5 min, recovery time of 9 min.
Graphene/MoS2 [146]	NH3	5 ppm	150 °C	Response time < 10 min, Recovery time < 30 min.
WS2 [148]	NH3	50 ppm	RT	Response time of 200 s, recovery time of 232.3 s.
MoS2 [121]	NH3	1 ppm	RT	Response time 5–9 min, recovery time < 15 min.
UV-treated MoS2 [139]	NH3	100 ppm	RT	Response time of 7 min, Recovery time of 12 min.
MoTe2 [147]	NH3	2 ppm	RT	Over 95% recovery using gate biases of 0 V and 20 V. Response time 10 min, recovery time 20 min.
MoS2/Co3O4 [150]	NH3	0.1 ppm	RT	Response time is 98 s, recovery time is 100 s.
PMMA-MoS2 [151]	NH3	1 ppm	RT	Sensitivity of 54%, response time of 10 s, recovery time of 14 s.
MoS2/VS2 [152]	NH3	5 ppm	40 °C	Recovery and response time both < 5 min.