Graphene-based Room Temperature Gas Sensing Materials

Gas sensing materials essentially dominate the performances of the gas sensors which are widely applied in environmental monitoring, industrial production and medical diagnosis. However, most of the traditional gas sensing materials show excellent performances only at high operating temperatures, which are high energy consumptive and have potential issues in terms of reliability and safety of the sensors. Therefore, the development of Room Temperature (RT) gas sensing materials becomes a research hotspot in this field. In recent years, graphene-based materials have been studied as a class of promising RT gas sensing materials because graphene has a unique twodimensional (2D) structure with high electron mobility and superior feasibility of assembling with other “guest components” (mainly small organic molecules, macromolecules and nanoparticles). More interestingly, its electrical properties become even more sensitive toward gas molecules at RT after surface modification. In this review, we have summarized the recently reported graphenebased RT gas sensing materials for the detection of NO₂, H₂S, NH₃, CO₂, CO, SO₂, Volatile Organic Compounds (VOCs) (i.e. formaldehyde, acetone, toluene, ethanol), as well as Liquefied Petroleum Gas (LPG) and highlighted the latest researches with respect to supramolecular modification of graphene for gas sensing. The corresponding structural features and gas sensing mechanisms of the graphene-based gas sensors have also been generalized.