Enhanced sensing response of the three dimensional MoS2 microstructure for NO2 gas detection at room temperature.

As a promising sensing material, Molybdenum disulfide (MoS₂) nanosheets is being increasingly studied for Nitrogen dioxide (NO₂) gas sensing. However, the MoS₂ nanosheets is prone to the stacking effect that compromises the sensing performances. Here, the stacking effect is mitigated by engineering MoS₂ nanosheets into a three dimensional (3D) network microstructure, which was fabricated by method of electrostatically self-assembling of MoS₂/SiO₂ microspheres. The fabricated sensor based on 3D MoS₂ network observed a significantly improved response of 15% to 12.3 ppm NO₂, which is a 75-fold increase compared to the control sensor with pure MoS₂ nanosheets. In addition, the sensitivity of the sensor with 3D MoS₂ network was 6.15 times larger than that of the control sensor with pure MoS₂ nanosheets. The detection limit of our sensor was 0.297 ppm, lower than most of reported MoS₂-based NO₂ sensors. The enhanced sensitivity and dynamic response stem from the improved interaction between NO₂ molecules and MoS₂ network, thanks to its increased surface area per footprint of MoS₂ nanosheets compared to pure 2D MoS[sub 2]<subscript /> film (single- or few-layer). This work presents a new approach to enhancing the performance of gas sensors based on 2D materials. [ABSTRACT FROM AUTHOR]