Adsorption of SF6 Decomposed Species on Ti3C2O2 and Ti3C2F2 with Point Defects by DFT Study

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Detail(s)

Original languageEnglish
Article number2100074
Journal / PublicationAdvanced Theory and Simulations
Volume4
Issue number7
Online published4 Jun 2021
Publication statusPublished - Jul 2021

Abstract

The high specific surface area and electrical conductivity of new 2D metal carbide MXenes make them become a suitable candidate as sensor platform of the gas sensor. Herein, density functional theory (DFT) is implemented to investigate the adsorption of the SF6 decomposed gases (SOF2, SO2, and H2S) on Ti3C2O2, Ti3C2F2, and Ti3C2(OH)2. Modification of the surface of Ti3C2O2 and Ti3C2F2 by O and F point vacancy, respectively, is then performed to improve the adsorption performance. The band structure, charge density differences, electron localization function (ELF), and projected density of states (PDOS) are investigated to study the adsorption mechanism. The results indicate that as compared with the weak adsorption on pristine Ti3C2O2 and Ti3C2F2, the SOF2, SO2, and H2S gas molecules tend to be chemisorbed on Ti3C2O2 and Ti3C2F2 with point vacancy with high adsorption energies. Furthermore, the study of electronic properties suggests that all adsorption systems show high electronic conductivity and the exposed Ti atoms by point defect mainly contribute to the formation of ionic bond with high adsorption energy. Thus, the present results show that Ti3C2O2 and Ti3C2F2 with point vacancy are feasible novel sensing materials to detect SF6 decomposed species with high sensitivity and low electronic noise. The sensitive detection capability of SO2 is particularly noticeable.

Research Area(s)

  • density functional theory, functional surfaces, gas sensors, MXenes, SF6 decomposed species