He adsorption and sensing properties of graphene nanoflakes doped with Mo and Nb

Abstract

DFT calculations have been performed to study the He adsorption on the surface of Mo-doped graphene and Nb-doped graphene nanoflakes in order to evaluate the capability of studied doped graphene sheets as effective gas sensor materials. The ωB97XD (including dispersion)/6-311++G(d,p) (LanL2DZ for Mo and Nb) level of theory were utilized in this investigation. The HOMO-LUMO gap (Eg) of the Mo-doped and Nb-doped graphene structures decreased upon He adsorption on both sheets (-37.77% and -8.33%, respectively). Therefore, the electrical conductivity of both surfaces have increased. However, alteration of the Eg value in Mo-doped graphene is very higher than that of Nb-doped graphene. So, the Mo-doped graphene is more sensitive to He molecule in comparison with Nb-doped graphene and it could be used as a gas sensor material to detect He gas. Variety analyses such as natural bond orbital (NBO), density of states (DOS), electron density distribution (ED), electron localization function (ELF) and non-covalent interaction-reduced density gradient (NCI-RDG) have been carried-out in order to better evaluate the He adsorption nature on the investigated surfaces.

Tailoring gas sensing properties of WS2 monolayer via Nb and Co embedding for highly sensitive and selective detection of HCN and H2S gases: a first principle study

“…Nonetheless, the lack of a band gap in graphene impedes its practical application, necessitating the development of alternative materials with an appropriate band gap. Thus, following the pioneering discovery of graphene, a subsequent generation of two-dimensional (2D) materials expeditiously surfaced, encompassing hexagonal boron nitride (BN) [7], boron carbon nitride (BNC) [8], transition metal dichalcogenides [9,10], and functionalized graphene [11,12] have been extensively investigated. Due to their large surface-to-volume ratio, high thermal stability, and seamless compatibility with device integration, several experimental studies have investigated the ability of 2D materials for gas sensing [13,14].…”