Enhanced sensing response of the three dimensional MoS2 microstructure for NO2 gas detection at room temperature
Hongdao Cheng, S.H. Huang, Zengshan Xing, Lu Yang, Jianhui Yu, Yongchun Zhong
Abstract
As a promising sensing material, Molybdenum disulfide (MoS 2 ) nanosheets is being increasingly studied for Nitrogen dioxide (NO 2 ) gas sensing. However, the MoS 2 nanosheets is prone to the stacking effect that compromises the sensing performances. Here, the stacking effect is mitigated by engineering MoS 2 nanosheets into a three dimensional (3D) network microstructure, which was fabricated by method of electrostatically self-assembling of MoS 2 /SiO 2 microspheres. The fabricated sensor based on 3D MoS 2 network observed a significantly improved response of 15% to 12.3 ppm NO 2 , which is a 75-fold increase compared to the control sensor with pure MoS 2 nanosheets. In addition, the sensitivity of the sensor with 3D MoS 2 network was 6.15 times larger than that of the control sensor with pure MoS 2 nanosheets. The detection limit of our sensor was 0.297 ppm, lower than most of reported MoS 2 -based NO 2 sensors. The enhanced sensitivity and dynamic response stem from the improved interaction between NO 2 molecules and MoS 2 network, thanks to its increased surface area per footprint of MoS 2 nanosheets compared to pure 2D MoS 2 film (single- or few-layer). This work presents a new approach to enhancing the performance of gas sensors based on 2D materials.