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DFT Calculations of Silver Atom Modified Tungsten Disulfide Monolayer as Promising Sensing Materials for Small Molecular Toxic Gases
oleh: Qi Zhao, Jin He, Songyuan Li, Suya Li, Qi Ning, Hao Cui
Format: | Article |
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Diterbitkan: | MDPI AG 2023-11-01 |
Deskripsi
In the contemporary context, the significance of detecting harmful gases cannot be overstated, as it profoundly affects both environmental integrity and human welfare. In this study, theoretically, density functional theory was employed to explore the adsorption behavior of three prevalent hazardous gases, namely CO, NO<sub>2</sub>, and SO<sub>2</sub>, on silver-atom-modified tungsten disulfide (WS<sub>2</sub>) monolayer. The multifaceted analysis encompasses an array of critical aspects, including the adsorption structure, adsorption energy, electron transfer, and charge density difference to unravel the adsorption behavior. Further exploration of electronic properties encompassing band structure, density of states (DOS), and work function was conducted. The ambit of our exploration extends to the desorption properties based on adsorption-free energies. Among these gas molecules, NO<sub>2</sub> stands out with the highest adsorption energy and the most substantial electron transfer. Notably, each of these adsorption processes triggers a redistribution of electron density, with NO<sub>2</sub> exhibiting the most pronounced effect. Furthermore, the adsorptions of CO, NO<sub>2</sub>, and SO<sub>2</sub> induce a noteworthy reduction in the band gap, prompting the reconfiguration of molecular orbitals. Additionally, the adsorption of these gases also leads to an increase in the work function of Ag-WS<sub>2</sub> to a different extent. Our investigation of desorption properties uncovers that Ag-WS<sub>2</sub> can adeptly function at ambient temperatures to detect CO and SO<sub>2</sub>. However, for NO<sub>2</sub> detection, higher temperatures become imperative due to the necessity for poison removal. The implications of our findings underscore the tremendous potential of Ag-WS<sub>2</sub> as a sensing material for detecting these hazardous gases. Our research extends to the broader realm of surface modification of transition metal dichalcogenides and their promising applications in the domain of gas sensing.