A DFT Study on the Adsorption of H₂S and SO₂ on Ni Doped MoS₂ Monolayer.

Huangli Wei,Yingang Gui,Jian Kang,Weibo Wang,Chao Tang

doi:10.3390/nano8090646

Huangli Wei, Yingang Gui + Show 3 more

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https://doi.org/10.3390/nano8090646

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Abstract

In this paper, a Ni-doped MoS2 monolayer (Ni-MoS2) has been proposed as a novel gas adsorbent to be used in SF6-insulated equipment. Based on the first-principles calculation, the adsorption properties of Ni-MoS2 to SO2 and H2S molecules, the main decomposition components of SF6 under a partial discharge (PD) condition have been studied. The adsorption energy, charge transfer, and structural parameters have been analyzed to find the most stable gas-adsorbed Ni-MoS2. Furthermore, the density of states (DOS), projected density of states (PDOS), and electron density difference were employed to explore the interaction mechanism between SO2, H2S, and the Ni-MoS2 surface. It is found that the H2S molecule and SO2 molecule interact with the Ni-MoS2 surface by strong adsorption energy. Therefore, we conclude that the interaction between these two kinds of gases and the Ni-MoS2 monolayer belongs to chemisorption, and the Ni-MoS2 monolayer might be a promising gas adsorbent for the fault recovery of SF6-insulated equipment. Additionally, we have to point out that all of the conclusions only considered the final adsorption energy, the barrier in the transition state has not been analyzed in this paper.

Highlights

Due to the excellent insulation and arc extinguishing properties of SF6, it has obtained a wide application in gas-insulated equipment, such as gas-insulated switchgear (GIS), gas-insulated breaker (GIB), and gas-insulated transformer (GIT)
Its gas adsorption performance towards the typical SF6 decomposition components H2S and SO2 has been systematically studied based on the analysis of structural parameters, total density of states (TDOS), projected density of states (PDOS), and electron density difference
As the most stable doping position of Ni on MoS2 monolayer is the top site of the Mo atom according to previous studies [24], only the structure of Ni-doped MoS2 monolayer (Ni-MoS2) with Ni doping on the top site of the Mo is discussed in this paper

Summary

Introduction

Due to the excellent insulation and arc extinguishing properties of SF6, it has obtained a wide application in gas-insulated equipment, such as gas-insulated switchgear (GIS), gas-insulated breaker (GIB), and gas-insulated transformer (GIT). In order to ensure the running stability of SF6-insulated equipment, the primary task is to maintain the purity of the filling gas, namely removing the decomposition components of SF6 [9,10]. Its gas adsorption performance towards the typical SF6 decomposition components H2S and SO2 has been systematically studied based on the analysis of structural parameters, TDOS, PDOS, and electron density difference. The gas adsorption mechanisms of the Ni-doped MoS2 monolayer to H2S and SO2 was obtained based on the research above. In order to ensure the practicability of the adsorbent, the adsorption property of the Ni-MoS2 monolayer towards SF6 molecule has been studied. The Ni-doped MoS2 monolayer shows an ideal adsorption property to the target gases, signifying that it is a promising novel gas adsorbent used to ensure the running stability of SF6-insulated equipment

Computational Details

Results and Discussion

Adsorption of H2S Gas on the Ni-MoS2 Monolayer

Conclusions