Abstract:
A design of an advanced sensing material, such as
MoS2, is imperative to enhance the sensing performance of a sensor.
Because their usage alone for developing a practical sensor is
impeditive owing to low gas response and slow response/recovery
kinetics. Here, we report a high-performance NO2 gas sensor
using a hybrid of temperature-assisted sulfur vacancy within the
edge-oriented vertically aligned MoS2 (Sv-MoS2) and crumpled
reduced graphene oxide (rGO) particles. Interestingly, the Sv-
MoS2 functionalized by optimized rGO concentration exhibited
a significant enhancement of response to NO2 (approximately
three times higher than that of pristine vertically aligned MoS2)
with fast response (<1 min) and complete recovery. Such a large
improvement in the sensing performance could be attributed to
controlled electrical/chemical sensitization level of MoS2 through
controllable vacancy and interface engineering. The vacancy
engineering offers abundant active sites through creating sulfur
vacancy in additionally rich edge active sites of vertically oriented
MoS2 for more electronic interaction with gas molecules. While
interfacing of p-type rGO particles with n-type MoS2 leads to
multiple out-of-plane vertical nano-heterojunctions as a sensitizing
configuration for boosting the performance of the sensor. This
paper opens up a new approach towards improving the sensing
activity of a 2D material via a synergistic vacancy and interface
engineering.
