Gas Sensing by Metal and Nonmetal Co-Doped Graphene on a Ni Substrate

Abstract

Gas sensors based on graphene are gaining more and more attention. The unique properties of the single-atom-thick, flexible, robust, and quanta-sensitive graphene make it an excellent candidate for sensors. However, its characteristics can be modified to suit specific applications by means of metal and nonmetal doping. In this systematic and detailed study, with the aid of density functional theory (DFT)-based simulations, we investigate the gas sensing capabilities of trapped transition-metal (TM) atoms at the graphene double vacancy (2VG). Eight different gas molecules, ranging from electron acceptors (Lewis acids) to donor species (Lewis bases), are investigated, namely, O 2 , NO 2 , NO, CO 2 , SO 2 , H 2 O, NH 3 , and CO. Four TM atoms Fe, Co, Ni, and Cu are considered as active sites for gas sensing. The effects of N-doping and the Ni(111) substrate are also examined. The performance of these systems in terms of stability, sensitivity, selectivity, and reusability is discussed for practical applications.

Pyridinic Dominance N-Doped Graphene: A Potential Material for SO2 Gas Detection

“…But from the device perspective, the major disadvantage of graphene is its zero-band gap, which makes it challenging to regulate the carrier density . Doping with a foreign atom is a major approach to fabricating a highly efficient graphene-based device via band gap engineering and enhancing surface reactivity. , Nitrogen is an excellent element for doping in graphene, having comparable atomic radii and electronegativity with carbon. Furthermore, an active region on the surface is generated by overlapping the charge and spin densities .…”

Ab-initio characterization of iron-embedded nitrogen-doped graphene as a toxic gas sensor

“…Nitrogen (N) doped graphene materials provide high reversible stability and selectivity over CH 4 , H 2 and N 2 [48]. Furthermore, an exciting class of catalysts is recently emerging as single atom catalyst (SACs) with mono dispersed single atom supported by a solid substrate [49]. Different metal oxides substrates of TiO 2 , CeO 2 and FeO x are being employed which have a drawback of poor stability and low conductivity.…”

Metal dimers embedded vertically in defect-graphene as gas sensors: a first-principles study

“…Also only after the adsorption of the three gases on Co 2 >gra, the original magnetic properties of the system were maintained, and the system was conditioned to be non-magnetic after adsorption of the other gases (Table S6, ESI †). Most previous magnetic gas sensors utilized the change in atomic magnetic moment as a monitor, 8,42 while the alternation in magnetism is undoubtedly more obvious and easilymeasurable. The Ni 2 >gra is NM, and will become FM, antiferromagnetic (AFM) and FM after adsorption of O 2 , NO and NO 2 , respectively.…”