Highly Sensitive Gas Sensing Material for Environmentally Toxic Gases Based on Janus NbSeTe Monolayer

Abstract

Recently, a new family of the Janus NbSeTe monolayer has exciting development prospects for two-dimensional (2D) asymmetric layered materials that demonstrate outstanding properties for high-performance nanoelectronics and optoelectronics applications. Motivated by the fascinating properties of the Janus monolayer, we have studied the gas sensing properties of the Janus NbSeTe monolayer for CO, CO2, NO, NO2, H2S, and SO2 gas molecules using first-principles calculations that will have eminent application in the field of personal security, protection of the environment, and various other industries. We have calculated the adsorption energies and sensing height from the Janus NbSeTe monolayer surface to the gas molecules to detect the binding strength for these considered toxic gases. In addition, considerable charge transfer between Janus monolayer and gas molecules were calculated to confirm the detection of toxic gases. Due to the presence of asymmetric structures of the Janus NbSeTe monolayer, the projected density of states, charge transfer, binding strength, and transport properties displayed distinct behavior when these toxic gases absorbed at Se- and Te-sites of the Janus monolayer. Based on the ultra-low recovery time in the order of μs for NO and NO2 and ps for CO, CO2, H2S, and SO2 gas molecules in the visible region at room temperature suggest that the Janus monolayer as a better candidate for reusable sensors for gas sensing materials. From the transport properties, it can be observed that there is a significant variation of I−V characteristics and sensitivity of the Janus NbSeTe monolayer before and after adsorbing gas molecules demonstrates the feasibility of NbSeTe material that makes it an ideal material for a high-sensitivity gas sensor.

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

“…Many reported sensing studies have suggested an adsorption energy of more than 0.30 eV shows better gas adsorption. 38,56 Interestingly, our calculated adsorption energies (E ad ) of all the gas molecules except H 2 as shown in Table 1 satisfy this criterion. Table 1 and the above Fig.…”

“…This eminent characteristics and its distinct transport properties were especially notable in a discrepancy in the I – V profile showing signatures of the Janus NbSeTe as a highly sensitive gas sensor (mainly for NO 2 gas) with a reformable scope. 38 Moreover, applying an electric field, strain, defect, etc. are also effectual approaches for the modulation of the sensing properties.…”

From fundamental to CO2 and COCl2 gas sensing properties of pristine and defective Si2BN monolayers

“…73 Similarly, the computed recovery time of CO 2 molecule is also lower than that of other nanomaterials such as 1T-HfTe 2 (33.7 ns), 74 SiBi (0.73 ps) 75 and NbSeTe (23.1 and 13.3 ps). 76 It should be noted that the charge transfer between Si 2 BN-ML and gas molecules is fundamentally associated with the electronegativity difference, chemical bonding properties as well as adsorption energy. As a general practice, the reasonable adsorption energy r1 eV is treated as the most suitable one for sensing applications with feeble chemisorption or steady physisorption.…”

Novel Janus MoSiGeN4 nanosheet: adsorption behaviour and sensing performance for NO and NO2 gas molecules

“…28 It is not unique, Dou et al found that the sensitivity of WTe 2 monolayer for CO, NO, and O 2 molecules is signicantly improved by constructing the Janus structure. 29 Inspired by the above research about Janus structure, [30][31][32] we envisaged to further enhance the adsorption performance of the MoSi 2 N 4 monolayer for NO and NO 2 molecules in this way. Excitingly, Yu et al proposed a 2D Janus structure of MoSiGeN 4 monolayer by rst-principles calculations, which indeed exhibited more excellent stability and semiconducting properties.…”