Cu- and Al-Decorated Monolayer TiSe2 for Enhanced Gas Detection Sensitivity: A DFT Study

Adsorption and Sensing Performance of Pt(1-3)-Modified TiSe2 for Dissolved Gas (CH4, C2H2, and CO) in Transformer Oil: A DFT Study

Based on density functional calculations, the adsorption and gas sensing properties of transition metal Pt(1-3)-modified TiSe2 for dissolved gas (CH4, C2H2, CO) in transformer oil were studied in this paper. Firstly, the stable structures, density of states, and energy bands of Pt(1-3)-modified TiSe2 were calculated. Then, the structure parameters, density of states, electrostatic potential distribution, and desorption time of Pt(1-3)-modified TiSe2 after adsorbing CH4, C2H2, and CO gas were calculated. The results show that the large binding energy between the transition metal Pt(1-3) modification and the TiSe2 substrate indicates that the modification systems have good structural stability. On the one hand, Pt(1-3) modification improves the conductivity of TiSe2. On the other hand, the transition metal Pt(1-3), which acts as the active site for gas adsorption, obviously enhances the gas adsorption effect, resulting in the significant charge transfer and a change in material conductivity. In summary, Pt(1-3)-modified TiSe2 significantly improves the adsorption and gas sensing performance of gas sensing materials for CH4, C2H2, and CO, which provides a new idea for the study of gas sensing materials for online monitoring of transformer working conditions.

Bimetallic Phthalocyanine Monolayers as Promising Materials for Toxic H2S, SO2, and SOF2 Gas Detection: Insights from DFT Calculations

The development of a high-performance gas sensor for the rapid and efficient detection of harmful SF6 decomposition gases (H2S, SO2, and SOF2) is crucial for equipment environmental monitoring and safeguarding human health. In this work, first-principles calculations were conducted to assess the adsorption performance and sensing characteristics of these decomposition gases on two-dimensional metal-dimer-modified phthalocyanine (Mn2Pc, Tc2Pc, and MnTcPc) surfaces. The results demonstrate that the Mn2Pc, Tc2Pc, and MnTcPc monolayers possess enhanced structural stability. The Mn2Pc, Tc2Pc, and MnTcPc monolayer materials show strong adsorption capabilities (|Eads| > 0.90 eV) and significant electron transfer (|Qt| > 0.017 e) and interact favorably with the aforementioned toxic gases, indicating their superior adsorption capacities for SOF2, SO2, and H2S. The microscopic interaction mechanisms between SF6-decomposed gas molecules and the Mn2Pc, Tc2Pc, and MnTcPc nanosheets are elucidated through analyses of electron density distribution, differential charge distribution, and density of states. Furthermore, upon absorption of H2S, SO2, and SOF2, the work function and band gap energy of the Mn2Pc, Tc2Pc, and MnTcPc monolayers undergo significant changes, and the magnetic moments of the Mn2Pc, Tc2Pc, and MnTcPc monolayers also exhibit substantial alterations, suggesting high sensitivity to H2S, SO2, and SOF2. Considering the balance of adsorption strength, sensitivity, and recovery time, the single-layer films of Mn2Pc, Tc2Pc, and MnTcPc are deemed to be gas-sensing materials with significant potential, suitable for the development of sustainable gas sensors targeting H2S, SO2, and SOF2 with effective recovery capabilities.

Pd-Adsorbed SiN3 Monolayer as a Promising Gas Scavenger for SF6 Partial Discharge Decomposition Components: Insights from the First-Principles Study

Gas-insulated switchgear (GIS) equipment must be protected by detecting and eliminating the toxic SF6 partial discharge decomposition components. This study employs first-principles calculations to thoroughly investigate the interaction between a Pd-adsorbed SiN3 monolayer (Pd-SiN3) and four typical SF6 decomposition gases (H2S, SO2, SOF2, and SO2F2). The study also investigates the associated geometric, electrical, and optical characteristics along with the sensing sensitivity and desorption efficiency. The ab initio molecular dynamics (AIMD) simulations demonstrated the favorable stability of the Pd-SiN3 monolayer. Furthermore, the Pd-SiN3 monolayer exhibited strong chemisorption behavior toward H2S, SO2, SOF2, and SO2F2 gases because of the higher adsorption energies of -2.717, -2.917, -2.457, and -2.025 eV, respectively. Furthermore, significant changes occur in the electronic and optical characteristics of the Pd-SiN3 monolayer following the adsorption of these gases, resulting in remarkable sensitivity of the Pd-SiN3 monolayer in relation to electrical conductivity and optical absorption. Meanwhile, all of these gas adsorption systems exhibited extremely long recovery times. The aforementioned theoretical findings suggest that the Pd-SiN3 monolayer has the potential to be an effective gas scavenger for the storage or removal of the SF6 decomposition components. Additionally, it might function as a reliable one-time sensor for detecting these gases. The results potentially provide valuable theoretical guidance for maintaining the normal operation of the SF6 insulation devices.