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

Tian

et al. 2021

Preprint

Density functional theory calculations have been made to investigated the adsorption and sensing properties of harmful nitrogen oxides (NO, NO2) on rhodium (Rh) doped hexagonal boron nitride (BN) to explore the feasibility of Rh-doped BN (Rh-BN) based gas sensor. For each gas molecule, various adsorption positions and orientations were examined. The favorable adsorption configuration has been established and the corresponding adsorption energy has been calculated. Besides, to understand the adsorption mechanism, The properties such as electron density, the energy band structure, state density of states, and charge transfer of the adsorption system were investigated in greater detail. The calculations indicate that the most stable structure is that the Rh atom located directly above the N atom, and a stable chemical bond with a length of 2.096 Å formed between the Rh atom and N atom, with a significant binding energy (𝐸𝑏) of -1.561 eV. Then, adsorption performance of Rh-BN monolayer upon nitrogen oxides is in order as NO2 > NO, with the adsorption energy (𝐸𝑎) of -3.919 eV and -3.318 eV, respectively. This indicates that the Rh-BN single layer possesses ideal adsorption and sensing properties. Furthermore, by doping the Rh atom, many levels of impurities are introduced into the intrinsic BN band structure, thereby improving the interaction between BN and adsorbed gas molecules. Following adsorption of NO and NO2, the band gap (Eg) of the doping system is wider. It has been demonstrated that gas adsorption reduces the electrical conductivity of the system, but increases the sensitivity of the system. The above calculation and analysis are of great importance for the exploration of the Rh-BN single layer as innovative gas detection material.

Section: Analysis Of Rh-bn Monolayer Structural Propertiesmentioning

confidence: 91%

Adsorption of NO, NO2 on Rh Embedded h-BN Monolayer: A First-Principles Study

Tian

et al. 2021

Preprint

“…s b and s a respectively mean the conductivity of single-layer Rh-BN before and after adsorbing gas. [24] Therefore, according to the relationship between conductivity and sensitivity, gas adsorption reduces the electrical conductivity of the system but improves its sensitivity. Furthermore, the PDOS of the Rh-BN/NO 2 adsorption system shows that there is a strong hybridization between the s orbital of Rh and the p orbital of N and O around À 10 eV, illustrating the established structure of the adsorption system is stable.…”

Section: Analysis Of Rh-bn/no 2 Adsorption System Structural Propertiesmentioning

confidence: 99%

Adsorption of NO and NO₂ on Rh‐Doped Hexagonal Boron Nitride Monolayers: A First‐Principles Study

et al. 2021

Density functional theory (DFT) calculations have been made to investigate the adsorption and sensing properties of harmful nitrogen oxides (NO, NO 2 ) on rhodium (Rh) doped hexagonal boron nitride (BN) to explore the feasibility of constructing Rhdoped BN (Rh-BN) based gas sensors. For each gas molecule, various adsorption positions and orientations were examined. The calculations illustrate that the most stable structure is that the Rh atom is located directly above the N atom, and a stable chemical bond with a length of 2.096 Å formed between the Rh atom and N atom, with significant binding energy (E b ) of À 1.561 eV. Moreover, the adsorption performance of the Rh-BN monolayer towards nitrogen oxide is in the order as NO 2 > NO, with E a of À 3.919 eV and À 3.318 eV, respectively. This indicates that the Rh-BN single layer possesses ideal adsorption and sensing properties. Furthermore, by doping the Rh atom, impurities are introduced into the intrinsic BN band structure, which improves the interaction between BN and adsorbed gas molecules. Following the adsorption of NO and NO 2 , the bandgap (E g ) of the doped BN is wider, which indicates that gas adsorption reduces the conductivity of the system, but enhances the sensitivity of the system. The above calculation and analysis are of great importance for the exploration of the Rh-BN monolayer as an innovative gas detection material.

“…However, these traditional gas sensors have defects, such as low sensitivity and instability, limiting their further development [ 10 , 11 ]. Two-dimensional (2D) materials are widely used in gas sensing, catalysis, energy storage, etc., due to their large specific surface areas and distinctive physical and chemical properties [ 12 , 13 , 14 ]. The MoS 2 monolayer was studied and reported as a potential gas-sensing material [ 15 ].…”

Section: Introductionmentioning

confidence: 99%

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

Liu

Wang

et al. 2021

Nanomaterials

Self Cite

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.