Adsorption, Gas-Sensing, and Optical Properties of Molecules on a Diazine Monolayer: A First-Principles Study

Abstract

Using first-principles calculations, the structural, electronic, and optical properties of CO 2 , CO, N 2 O, CH 4 , H 2 , N 2 , O 2 , NH 3 , acetone, and ethanol molecules adsorbed on a diazine monolayer were studied to develop the application potential of the diazine monolayer as a room-temperature gas sensor for detecting acetone, ethanol, and NH 3 . We found that these molecules are all physically adsorbed on the diazine monolayer with weak adsorption strength and charge transfer between the molecules and the monolayer, but the physisorption of only NH 3 , acetone, and ethanol remarkably modified the electronic properties of the diazine monolayer, especially for the obvious change in electric conductivity, showing that the diazine monolayer is highly sensitive to acetone, NH 3 , and ethanol. Further, the adsorption of NH 3 , acetone, and ethanol molecules remarkably modifies, in varying degrees, the optical properties of the diazine monolayer, such as work function, absorption coefficient, and the reflectivity, whereas adsorption of other molecules has infinitesimal influence. The different adsorption behaviors and influences of the electronic and optical properties of molecules on the monolayer show that the diazine monolayer has high selectivity to NH 3 , acetone, and ethanol. The recovery time of NH 3 , acetone, and ethanol molecules is, respectively, 1.2 μs, 7.7 μs, and 0.11 ms at 300 K. Thus, the diazine monolayer has a high application potential as a room-temperature acetone, ethanol, and NH 3 sensor with high performance (high selectivity and sensitivity, and rapid recovery time).

Selective and sensitive toxic gas-sensing mechanism in a 2D Janus MoSSe monolayer

“…This specific variation in work function could enable MoSSe to serve as an Φ -type gas sensor for NO 2 , SO 2 and NO detection. 59–61 Moreover, it was shown that the physical adsorption of other gases NH 3 , HCN, CO 2 , CO, H 2 and H 2 S did not alter the work function considerably. Thus, the work function results indicated a high possibility of chemisorption of NO 2 on the Se site of the MoSSe monolayer.…”

“…This specific variation in work function could enable MoSSe to serve as an F-type gas sensor for NO 2 , SO 2 and NO detection [59][60][61]. Moreover, it was shown that the physical adsorption of other gases NH 3 , HCN, CO 2 , CO, H 2 and H 2 S did not alter the work function considerably.…”

Ultra-responsive and highly sensitive 1D ZnO nanotubes for detecting perilous low levels of NO2 gas

“…[1][2][3][4][5][6] Some of the most common polluting gases include hydrogen disulfide (H 2 S), nitrogen dioxide (NO 2 ), acetone, and ammonia (NH 3 ). [7][8][9][10] These gases have considerable health repercussions and are significant contributors to lung diseases like emphysema, respiratory irritation syndrome, and chronic obstructive pulmonary disease. [11][12][13] In particular, NO 2 is a highly toxic gas and is a major contributor to air pollution.…”

First-Principles Investigation of Adsorption Behaviors and Electronic, Optical, and Gas-Sensing Properties of Pure and Pd-Decorated GeS2 Monolayers

“…Since its discovery in 2004, graphene has presented many fascinating properties, but its zero band-gap feature critically limits its myriad of applications in transistors, electronics, photonics, etc. − Although the modification of graphene can effectively open its band gap, this also reduces the electronic quality of the material, which is impractical for device applications. − This situation has stimulated scientists to design and investigate two-dimensional (2D) materials with semiconducting properties. Researchers have directed their studies to materials with layered honeycomb structures similar to that of graphite. − One of the most widely studied classes of these materials is 2D transition metal disulfides (TMDs). − 2D TMDs, which are nanomaterials in the formula of MX 2 , M are TM atoms, such as Mo, W, and Ge, sandwiched between two X atoms (i.e., VIA group like S, Se, and Te), are structurally similar to graphene (i.e., owning hexagonal structures), but compensate for the zero band-gap of graphene. The participation of TM d-electrons with different numbers makes 2D TMDs exhibit different electrical properties, such as semiconducting with band-gap widths of about 1–2 eV, metallic, semiconductivity, and charge density wave behaviors, and thus have attracted remarkable interest for their potential applications in field-effect transistors, gas sensors, optical sensors, lubricants, etc. − …”