Adsorption of phosgene on Si-embedded MoS2 sheet and electric field-assisted desorption: insights from DFT calculations

• Published in: Journal of materials science Vol. 54; no. 17; pp. 11497 - 11508
• Main Authors: Sharma, Archana, Khan, Mohd. Shahid, Husain, Mushahid
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2019; Springer Nature B.V
• Subjects: Adsorption; Characterization and Evaluation of Materials; Charge density; Charge transfer; Chemistry and Materials Science; Classical Mechanics; Computation & Theory; Crystallography and Scattering Methods; Density functional theory; Dipole interactions; Electric fields; Materials Science; Mathematical analysis; Molybdenum disulfide; Phosgene; Polymer Sciences; Silicon; Solid Mechanics; Stability analysis; Work functions
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-019-03706-2

In quest of effective materials and technologies for detecting toxic gas molecules, an attempt is made to detect phosgene gas molecule using MoS 2 by employing dispersion corrected density functional theory calculations. Doping Si into the S-vacancy of MoS 2 monolayer results in improvement of adsorption capability of phosgene gas molecule, reaching adsorption energy of − 1.228 eV. It is revealed that Si-doped MoS 2 sheet is thermodynamically stable at high temperatures, and hence, room temperature stability is expected. Origin of interaction between phosgene and adsorbent is analyzed by calculating density of states, charge transfer, and vibrational frequency. Strong binding and more charge transfer modulate band gap and work function of the Si-doped MoS 2 material post-phosgene adsorption indicate that such system is highly sensitive to phosgene. It is further shown that the sensing material is completely recovered by applying 0.6 V/Å magnitude vertical positive electric field. The reason for reduced stability of the system is revealed by variations in charge transfer process and induced dipole interaction due to the charge redistribution. The results suggest potential application of MoS 2 -based sheets for sensing phosgene gas molecule, where external electric field efficiently aids reversible adsorption process.