First-Principles Study of Au-Doped InN Monolayer as Adsorbent and Gas Sensing Material for SF6 Decomposed Species

Abstract

As an insulating medium, sulfur hexafluoride (SF6) is extensively applied to electrical insulation equipment to ensure its normal operation. However, both partial discharge and overheating may cause SF6 to decompose, and then the insulation strength of electrical equipment will be reduced. The adsorption properties and sensing mechanisms of four SF6 decomposed components (HF, SO2, SOF2 and SO2F2) upon an Au-modified InN (Au-InN) monolayer were studied in this work based on first-principles theory. Meanwhile, the adsorption energy (Ead), charge transfer (QT), deformation charge density (DCD), density of states (DOS), frontier molecular orbital and recovery property were calculated. It can be observed that the structures of the SO2, SOF2 and SO2F2 molecules changed significantly after being adsorbed. Meanwhile, the Ead and QT of these three adsorption systems are relatively large, while that of the HF adsorption system is the opposite. These phenomena indicate that Au-InN monolayer has strong adsorption capacity for SO2, SOF2 and SO2F2, and the adsorption can be identified as chemisorption. In addition, through the analysis of frontier molecular orbital, it is found that the conductivity of Au-InN changed significantly after adsorbing SO2, SOF2 and SO2F2. Combined with the analysis of the recovery properties, since the recovery time of SO2 and SO2F2 removal from Au-InN monolayer is still very long at 418 K, Au-InN is more suitable as a scavenger for these two gases rather than as a gas sensor. Since the recovery time of the SOF2 adsorption system is short at 418 K, and the conductivity of the system before and after adsorption changes significantly, Au-InN is an ideal SOF2 gas-sensing material. These results show that Au-InN has broad application prospects as an SO2, SOF2 and SO2F2 scavenger and as a resistive SOF2 sensor, which is of extraordinary meaning to ensure the safe operation of power systems. Our calculations can offer a theoretical basis for further exploration of gas adsorbent and resistive sensors prepared by Au-InN.

Highly sensitive work function type room temperature gas sensor based on Ti doped hBN monolayer for sensing CO2, CO, H2S, HF and NO. A DFT study

“…The bond angles, O-C-O of CO 2 and H-F-H of H 2 S gas molecules are 180°and 92.1°respectively. These values of structural parameters of gas molecules in our work are consistent with previous reports [49][50][51].…”

“…These values of structural parameters of gas molecules in our work are consistent with previous reports. 49–51…”

“…These values of structural parameters of gas molecules in our work are consistent with previous reports. [49][50][51] 3.1.3. CO 2 , CO, H 2 S, HF and NO adsorption on pristine hBN monolayer.…”

Adsorption and Sensing Performances of Pristine and Au-Decorated Gallium Nitride Monolayer to Noxious Gas Molecules: A DFT Investigation

“…Noble metals, as an activator, change the electronic state of the pristine material and can greatly enhance the selectivity and response speed of gas-sensitive materials and reduce their working temperature ( Zhou et al, 2018b ). For example, Peng et al (2021) , by comparing the adsorption with the intrinsic InN, found that the absorption characteristic for Au–InN to the SF 6 -decomposed gases remains superior to InN, reflecting the good electron mobility of Au doping. Moreover, Dong et al (2011) reported the response of noble metal Pt-decorated SnO 2 nanofibers to gas H 2 S and obtained that the gas-sensitive response rate of 0.08wt% Pt-decorated SnO 2 nanofibers to H 2 S was 25.9–40.6 times higher than that of pristine SnO 2 nanofibers, which proved that noble metal doping can greatly improve the gas-sensitive response.…”

Adsorption Mechanism of SO2 on Transition Metal (Pd, Pt, Au, Fe, Co and Mo)-Modified InP3 Monolayer

“…As is well known, modifying and doping the base material with a transition metal (TM) can enhance electron mobility and promote the chemical activity of the base material, thus enhancing the gas adsorption capacity. The TM usually plays an essential role in improving the selectivity and sensitivity of nanomaterials to target gases [30][31][32]. In existing research, various doping atoms are used, but Pd, Pt, Au, Fe, Co and Mo as dopants have excellent doping and adsorption effects [33][34][35][36][37][38].…”