Pt Cluster Modified h-BN for Gas Sensing and Adsorption of Dissolved Gases in Transformer Oil: A Density Functional Theory Study

Adsorption and Sensing Mechanism of a nTiO2 Particle (n = 1-3)-Doped MoTe2 Monolayer to Faulty and Hazardous Gases in the Underground Cableway

With the rapid growth of the economy and industrial technology, vigoroso and stable power distribution networks have gradually been established worldwide. Among these networks, underground cables play a crucial role in the distribution process, determining the overall electrical stability of entire cities. Based on density functional theory, this paper first proposes a TiO2 particle-doped MoTe2 monolayer to detect and eliminate these faults and hazardous gases within the underground cableway. The band structure, total density of states, projected density of states, and differential charge density are analyzed. The results demonstrate that the presence of TiO2 particles significantly enhances the adsorption capacity of MoTe2, diminishes the electrical conductivity of the doping system, and heightens electron activity in the doping reaction zone. The best adsorption performance is achieved in the case of two-particle doping. Furthermore, the modified MoTe2 exhibits an enhanced capability for capturing SO2 and SOF2, with the adsorption mechanism classified as physical-chemical adsorption. This work not only introduces a novel surface modification method for a MoTe2 monolayer but also provides a substantial data set to support the design and production of efficient sensors used in the underground cableway. These contributions further enhance the safety and stability of power systems and ensure human health.

Adsorption Mechanisms of TM3 (TM = Mo, Ru, Au)-Decorated Tin Sulfide Monolayers for the Decomposition of Gas Components under Fault Conditions in Oil-Immersed Transformers

Oil-immersed transformers play a pivotal role owing to their environmentally friendly characteristics, compact footprint, and cost-effectiveness. Ensuring the online monitoring of oil-immersed transformers is a fundamental measure to ensure the secure and stable operation of modern power systems. In this paper, metal particle cluster-doped SnS is firstly used in the adsorption and sensing of decomposition components (CO, C2H2) under fault conditions in oil-immersed transformers. The study comprehensively analyzed band structure, differential charge density, density of states, and molecular orbital theory to unveil the adsorption and sensing mechanisms of target gases. The findings suggest that the modification of metal particle clusters can enhance the surface electronic properties of single-layer SnS. In the regions of metal particle clusters and the gas-surface reaction area, electronic activity is significantly heightened, primarily attributed to the contribution of d-orbital electrons of the metal cluster structures. The modified SnS exhibits adsorption capacity in the following order: Ru3-SnS > Mo3-SnS > Au3-SnS. Additionally, the modified material demonstrates increased competitiveness for C2H2, with adsorption types falling under physical chemistry adsorption. Different metal elements exert diverse effects on the electronic distribution of the entire system, providing a theoretical foundation for the preparation of corresponding sensors. The findings in this work offer numerical insights for the further preparation and development of SnS nanosensors, concurrently shedding light on the online monitoring of faults in oil-immersed transformers.

Adsorption and Gas-Sensing Properties of Agn (n = 1-4) Cluster Doped GeSe for CH4 and CO Gases in Oil-Immersed Transformer

The adsorption mechanism of CO and CH₄ on GeSe, modified with the most stable 1-4 Ag-atom clusters, is studied with the help of density functional theory. Adsorption distance, adsorption energy, total density of states (TDOS), projected density of states (PDOS), and molecular orbital theory were all used to analyze the results. CO was found to chemisorb exothermically on GeSe, independent of Ag cluster size, with Ag₄-GeSe representing the optimum choice for CO gas sensors. CH₄, in contrast, was found to chemisorb on Ag-GeSe and Ag₂-GeSe and to physisorb on Ag₃-GeSe and Ag₄-GeSe. Here, Ag GeSe was found to be the optimum choice for CH₄ gas sensors. Overall, our calculations suggest that GeSe modified by Ag clusters of different sizes could be used to advantage to detect CO and CH₄ gas in ambient air.

Adsorption of Greenhouse Decomposition Products on Ag2O-SnS2 and CuO-SnS2 Surfaces

In this paper, based on density functional theory, the adsorption mechanism and gas sensitivity of Ag₂O/CuO-modified SnS₂ were analyzed. The results were analyzed according to the adsorption energy, total density of states, partial density of states, and frontier molecular orbital theory. The results show that the adsorption of all gas molecules is exothermic. NH₃, Cl₂, and C₂H₂ gases are chemisorbed on the modified SnS₂ surfaces. After gas adsorption, the energy gap of the base changes by more than 10%, which fully shows that the conductivity changes greatly after gas adsorption, which can be reflected in the macroscopic resistance change. Ag₂O-SnS₂ is suitable as a gas sensor for NH₃ gas sensors in terms of moderate adsorption distance, large adsorption energy, charge transfer, and frontier molecular orbital theory, while CuO-SnS₂ is more suitable as a C₂H₂ gas sensor.

Adsorption of nitrogen oxide on modified BN nanosheets: Improved gas sensing and functionalization

The sensing mechanism of modified hexagonal boron nitride to nitrogen oxide molecules (NO, NO2 and N2O) was systematically investigated by using the density functional theory calculations. The results indicate that...

Visualization of Transition Metal Decoration on h-BN Surface

Functional h-BN (hexagonal boron nitride) has been prepared via the incorporation of transition metal (TM) impurities like nanoparticles and single atoms. Herein, scanning transmission electron microscopy (STEM) combined with density functional theory (DFT) was employed to study Ta-, Co-, Ni-, and Ir-decorated h-BN monolayers to provide an overview of their preferential site occupancies and morphological evolutions on h-BN. Ta, Ni, Ir, and Co single atoms are all positioned on the nitrogen of h-BN; however DFT predicts the occupancy site can vary with their spin state. In terms of microstructural evolution, Co, Ni, and Ir atoms form 3D nanoclusters while Ta atoms are well dispersed and thus the single Ta atom can be decorated on h-BN. This study highlights on TM/h-BN interaction dynamics and presents an avenue for designing nanostructures for electrocatalytic application.

The Adsorption and Sensing Performances of Ir-modified MoS2 Monolayer toward SF6 Decomposition Products: A DFT Study

In this paper, the Ir-modified MoS₂ monolayer is suggested as a novel gas sensor alternative for detecting the characteristic decomposition products of SF₆, including H₂S, SO₂, and SOF₂. The corresponding adsorption properties and sensing behaviors were systematically studied using the density functional theory (DFT) method. The theoretical calculation indicates that Ir modification can enhance the surface activity and improve the conductivity of the intrinsic MoS₂. The physical structure formation, the density of states (DOS), deformation charge density (DCD), molecular orbital theory analysis, and work function (WF) were used to reveal the gas adsorption and sensing mechanism. These analyses demonstrated that the Ir-modified MoS₂ monolayer used as sensing material displays high sensitivity to the target gases, especially for H₂S gas. The gas sensitivity order and the recovery time of the sensing material to decomposition products were reasonably predicted. This contribution indicates the theoretical possibility of developing Ir-modified MoS₂ as a gas sensor to detect characteristic decomposition gases of SF₆.

Application of WO3 Hierarchical Structures for the Detection of Dissolved Gases in Transformer Oil: A Mini Review

Oil-immersed power transformers are considered to be one of the most crucial and expensive devices used in power systems. Hence, high-performance gas sensors have been extensively explored and are widely used for detecting fault characteristic gases dissolved in transformer oil which can be used to evaluate the working state of transformers and thus ensure the reliable operation of power grids. Hitherto, as a typical n-type metal-oxide semiconductor, tungsten trioxide (WO₃) has received considerable attention due to its unique structure. Also, the requirements for high quality gas detectors were given. Based on this, considerable efforts have been made to design and fabricate more prominent WO₃ based sensors with higher responses and more outstanding properties. Lots of research has focused on the synthesis of WO₃ nanomaterials with different effective and controllable strategies. Meanwhile, the various morphologies of currently synthesized nanostructures from 0-D to 3-D are discussed, along with their respective beneficial characteristics. Additionally, this paper focused on the gas sensing properties and mechanisms of the WO₃ based sensors, especially for the detection of fault characteristic gases. In all, the detailed analysis has contributed some beneficial guidance to the exploration on the surface morphology and special hierarchical structure of WO₃ for highly sensitive detection of fault characteristic gases in oil-immersed transformers.