Alfalasi, Wadha; Hussain, Tanveer; Tit, Nacir

Author(s)

Alfalasi, Wadha

Hussain, Tanveer

Tit, Nacir

Publication Date

2024

Abstract

The gas-sensing properties of selected transition metal (TM) atoms functionalizing molybdenum disulfide (MoS2) monolayers as catalysts towards toxic nitrogen-containing gases (e.g., NO and NO2) were investigated using a combination of density-functional theory (DFT) and non-equilibrium Green's function (NEGF) formalism. Pristine MoS2 adsorbed NO and NO2 with relatively weak adsorption energies of −0.11 and −0.19 eV, respectively. To enhance the adsorption mechanism, five doping states were considered, such as (i) sulfur vacancies "VS" and (ii) Mn, (iii) Fe, (iv) Co, and (v) Ni dopants substituting the S-site in MoS2. We found that S vacancy-induced and Mn-, Fe-, Co-, and Ni-doped MoS2 resulted in significantly strong adsorption energies of −2.59 (−2.76), −2.16 (−1.17), −2.87 (−1.85), −3.06 (−1.61), and −1.97 (−0.90) eV for NO (NO2), respectively. The results of the electronic structure calculations showed that the adsorption of NO and NO2 drastically changed the magnetic states of the substrate, for instance from paramagnetic to ferromagnetic (FM) semiconducting states (e.g., VS and Ni-doping) and from FM to either antiferromagnetic (AFM) or paramagnetic semiconducting states (e.g., Mn- or Ni-doping, respectively). The results of current–voltage (I–V) characteristics showed that Co- and Ni-doping yielded the optimal sensor response which was attributed to the changes between two extreme magnetic states, for instance, from FM to paramagnetic semiconducting states and vice versa (e.g., Co- and Ni-doping, respectively). Our refined study of selectivity using seven gases (i.e., CO, CO2, N2, O2, H2, NO, and NO2) demonstrated that MoS2:Co and MoS2:Ni are potential materials for disposable gas sensors for the capture and the detection of toxic NO and NO2 gases.

Citation

Environmental Science: Nano, v.11, p. 1740-1754

ISSN

2051-8161

2051-8153

Link

https://hdl.handle.net/1959.11/58517

Publisher

Royal Society of Chemistry

Title

Functionalized molybdenum disulfide (MoS2) monolayer as an efficient nanosensor towards toxic nitrogen containing gases

Type of document

Journal Article

Entity Type

Publication

Author(s)	Alfalasi, Wadha Hussain, Tanveer Tit, Nacir
Publication Date	2024
Abstract	<p>The gas-sensing properties of selected transition metal (TM) atoms functionalizing molybdenum disulfide (MoS<sub>2</sub>) monolayers as catalysts towards toxic nitrogen-containing gases (e.g., NO and NO<sub>2</sub>) were investigated using a combination of density-functional theory (DFT) and non-equilibrium Green's function (NEGF) formalism. Pristine MoS<sub>2</sub> adsorbed NO and NO<sub>2</sub> with relatively weak adsorption energies of −0.11 and −0.19 eV, respectively. To enhance the adsorption mechanism, five doping states were considered, such as (i) sulfur vacancies "VS" and (ii) Mn, (iii) Fe, (iv) Co, and (v) Ni dopants substituting the S-site in MoS<sub>2</sub>. We found that S vacancy-induced and Mn-, Fe-, Co-, and Ni-doped MoS<sub>2</sub> resulted in significantly strong adsorption energies of −2.59 (−2.76), −2.16 (−1.17), −2.87 (−1.85), −3.06 (−1.61), and −1.97 (−0.90) eV for NO (NO<sub>2</sub>), respectively. The results of the electronic structure calculations showed that the adsorption of NO and NO<sub>2</sub> drastically changed the magnetic states of the substrate, for instance from paramagnetic to ferromagnetic (FM) semiconducting states (e.g., VS and Ni-doping) and from FM to either antiferromagnetic (AFM) or paramagnetic semiconducting states (e.g., Mn- or Ni-doping, respectively). The results of current–voltage (I–V) characteristics showed that Co- and Ni-doping yielded the optimal sensor response which was attributed to the changes between two extreme magnetic states, for instance, from FM to paramagnetic semiconducting states and vice versa (e.g., Co- and Ni-doping, respectively). Our refined study of selectivity using seven gases (i.e., CO, CO<sub>2</sub>, N<sub>2</sub>, O<sub>2</sub>, H<sub>2</sub>, NO, and NO<sub>2</sub>) demonstrated that MoS<sub>2</sub>:Co and MoS<sub>2</sub>:Ni are potential materials for disposable gas sensors for the capture and the detection of toxic NO and NO<sub>2</sub> gases.</p>
Citation	Environmental Science: Nano, v.11, p. 1740-1754
ISSN	2051-8161 2051-8153
Link	https://hdl.handle.net/1959.11/58517
Publisher	Royal Society of Chemistry
Title	Functionalized molybdenum disulfide (MoS2) monolayer as an efficient nanosensor towards toxic nitrogen containing gases
Type of document	Journal Article
Entity Type	Publication

Functionalized molybdenum disulfide (MoS2) monolayer as an efficient nanosensor towards toxic nitrogen containing gases

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