Effect of Measurement System Configuration and Operating Conditions on 2D Material-Based Gas Sensor Sensitivity

Abstract

Gas sensors applied in real-time detection of toxic gas leakage, air pollution, and respiration patterns require a reliable test platform to evaluate their characteristics, such as sensitivity and detection limits. However, securing reliable characteristics of a gas sensor is difficult, owing to the structural difference between the gas sensor measurement platform and the difference in measurement methods. This study investigates the effect of measurement conditions and system configurations on the sensitivity of two-dimensional (2D) material-based gas sensors. Herein, we developed a testbed to evaluate the response characteristics of MoS2-based gas sensors under a NO2 gas flow, which allows variations in their system configurations. Additionally, we demonstrated that the distance between the gas inlet and the sensor and gas inlet orientation influences the sensor performance. As the distance to the 2D gas sensor surface decreased from 4 to 2 mm, the sensitivity of the sensor improved to 9.20%. Furthermore, when the gas inlet orientation was perpendicular to the gas sensor surface, the sensitivity of the sensor was the maximum (4.29%). To attain the optimum operating conditions of the MoS2-based gas sensor, the effects of measurement conditions, such as gas concentration and temperature, on the sensitivity of the gas sensor were investigated.

Recent developments in 2D MXene-based materials for next generation room temperature NO2 gas sensors

“…Accurate measurement of NO 2 gas under real environmental conditions at room temperature with high selectivity, and reversibility at low cost is a challenging task. [7][8][9] In the past few decades, electrical signal-based NO 2 gas detection has been reported using sensors made of a variety of materials including metallic nanoparticles/metal-oxide, 10-14 polymers 13,[15][16][17] and two-dimensional materials (2D) such as MoS 2 . [18][19][20][21] Recently, there has been a lot of interest in research on 2D materials, including MXenes, because of their properties like high surface area to volume ratio, layer-dependent tuneable mechanical, electrical, optical, and physicochemical properties arising from quantum connement, and low dimensionality effects.…”

“…Accurate measurement of NO 2 gas under real environmental conditions at room temperature with high selectivity, and reversibility at low cost is a challenging task. 7–9…”