ABSTRACT
Nanomaterials are widely preferred over other materials for gas sensing due to their unique and outstanding properties, such as extremely high surface-to-volume ratio [1]. The foretold property can potentially lead to novel sensors with exceptional performance while reducing the device size and minimizing energy consumption [1]. In addition, the electron transport through graphene is highly sensitive to the adsorbed molecules owing to the two-dimensional structure of graphene that makes every carbon atom a surface atom [1]. Graphene has been demonstrated as a promising gas-sensing material [1-3]; for instance, Sheehan et al. [3] reported that mechanically exfoliated graphene can potentially detect gaseous species down to the single molecular level. The gas-sensing mechanism of graphene is generally ascribed to the adsorption/desorption of gaseous molecules (which act as electron donors or acceptors) on the graphene surface, which leads to changes in the conductance of graphene [1,2].
