Nanostructured Materials for Room‐Temperature Gas Sensors

Abstract

Sensor technology has an important effect on many aspects in our society, and has gained much progress, propelled by the development of nanoscience and nanotechnology. Current research efforts are directed toward developing high-performance gas sensors with low operating temperature at low fabrication costs. A gas sensor working at room temperature is very appealing as it provides very low power consumption and does not require a heater for high-temperature operation, and hence simplifies the fabrication of sensor devices and reduces the operating cost. Nanostructured materials are at the core of the development of any room-temperature sensing platform. The most important advances with regard to fundamental research, sensing mechanisms, and application of nanostructured materials for room-temperature conductometric sensor devices are reviewed here. Particular emphasis is given to the relation between the nanostructure and sensor properties in an attempt to address structure-property correlations. Finally, some future research perspectives and new challenges that the field of room-temperature sensors will have to address are also discussed.

Thin 2D: The New Dimensionality in Gas Sensing

“…Physical adsorption dominates at relatively low operating temperatures, so this approach is an advantage for minimizing power consumption of sensors and increasing their life-time [26]. Based on the physisorption-based charge transfer, Ou et The red and blue colors in the charge density distribution indicate the maximum and zero electronic densities, respectively.…”

“…The sensing mechanism of TMDs layered nanomaterials is instead typically based on physisorption-charge transfer processes [25]. Physical adsorption dominates at relatively low operating temperatures, so this approach is an advantage for minimizing power consumption of sensors and increasing their life-time [26]. Based on the physisorption-based charge transfer, Ou et al integrated 2D SnS 2 flakes onto low-cost resistive transducing platforms for highly selective and exceptionally sensitive NO 2 gas sensing at ppb levels [27].…”

A 3D Chemically Modified Graphene Hydrogel for Fast, Highly Sensitive, and Selective Gas Sensor

“…The production and emission of toxic gases in industry and agriculture increasingly endanger the health of human beings in the long term 1, 2, 3, 4. For example, NO 2 gas acts as a source of acid rain and contributes to the formation of ozone (O 3 ), which is the major cause of photochemical smog 5, 6.…”

Room temperature vanadium dioxide–carbon nanotube gas sensors made via continuous hydrothermal flow synthesis

“…Nanomaterials have shown promise for sensing of low concentrations of analyte, due to their high surface area and electronic properties that are affected by the local environment [3][4][5] . In some cases, the particular application and nanomaterial characteristics, permit sensor operation at room temperature, resulting in lower power consumption and increasing sensor suitability for use in portable devices 6 . The development of such materials is key to realising their application in sensors for personal health 7 , environmental 8 and agricultural monitoring 9 .…”