Formaldehyde Molecules Adsorption on Zn Doped Monolayer MoS2: A First-Principles Calculation

Huili Li; Ling Fu; Chaozheng He; Jinrong Huo; Houyong Yang; Tingyue Xie; Guozheng Zhao; Guohui Dong

doi:10.3389/fchem.2020.605311

Formaldehyde Molecules Adsorption on Zn Doped Monolayer MoS₂: A First-Principles Calculation

Front Chem. 2021 Apr 16:8:605311. doi: 10.3389/fchem.2020.605311. eCollection 2020.

Authors

Huili Li¹, Ling Fu^{2

3}, Chaozheng He^{4

5}, Jinrong Huo⁴, Houyong Yang^{4

5}, Tingyue Xie⁶, Guozheng Zhao¹, Guohui Dong⁷

Affiliations

¹ Key Laboratory of Magnetic Molecules, Magnetic Information Materials Ministry of Education, The School of Chemistry and Material Science, Shanxi Normal University, Linfen, China.
² College of Agricultural Engineering, Nanyang Normal University, Nanyang, China.
³ College of Resources and Environmental Engineering, Tianshui Normal University, Tianshui, China.
⁴ Institute of Environmental and Energy Catalysis, School of Materials Science and Chemical Engineering, Xi'an Technological University, Xi'an, China.
⁵ Shaanxi Key Laboratory of Optoelectronic Functional Materials and Devices, School of Materials Science and Chemical Engineering, Xi'an Technological University, Xi'an, China.
⁶ School of Physics and Electronic Science, Shanxi Datong University, Shanxi, China.
⁷ School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, China.

Abstract

Based on the first principles of density functional theory, the adsorption behavior of H₂CO on original monolayer MoS₂ and Zn doped monolayer MoS₂ was studied. The results show that the adsorption of H₂CO on the original monolayer MoS₂ is very weak, and the electronic structure of the substrate changes little after adsorption. A new kind of surface single cluster catalyst was formed after Zn doped monolayer MoS₂, where the ZnMo₃ small clusters made the surface have high selectivity. The adsorption behavior of H₂CO on Zn doped monolayer MoS₂ can be divided into two situations. When the H-end of H₂CO molecule in the adsorption structure is downward, the adsorption energy is only 0.11 and 0.15 eV and the electronic structure of adsorbed substrate changes smaller. When the O-end of H₂CO molecule is downward, the interaction between H₂CO and the doped MoS₂ is strong leading to the chemical adsorption with the adsorption energy of 0.80 and 0.98 eV. For the O-end-down structure, the adsorption obviously introduces new impurity states into the band gap or results in the redistribution of the original impurity states. All of these may lead to the change of the chemical properties of the doped MoS₂ monolayer, which can be used to detect the adsorbed H₂CO molecules. The results show that the introduction of appropriate dopant may be a feasible method to improve the performance of MoS₂ gas sensor.

Keywords: H2CO; adsorption energy; first-principles calculation; gas sensitivity; monolayer MoS2.