Browse
Submit Data
Databases
API
Help

Dataset Information

21 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Adsorption of SF₆ Decomposed Products over ZnO(1010): Effects of O and Zn Vacancies.

ABSTRACT: We carried out a density functional theory study to investigate the adsorption behavior of four kinds of SF₆ decomposed products over the ZnO(101̅0) surface. The effects of O and Zn vacancies on the surface were also considered. For perfect ZnO(101̅0) surface, the adsorption of SO₂ and H₂S exhibits stronger chemical interactions compared to the adsorption of SOF₂ and SO₂F₂. For SO₂ and H₂S adsorption, there may exist new chemical bond formation between the molecule and the surface and the H₂S molecule experiences one H-S broken bond. The introduction of O vacancy cannot obviously enhance the chemical interactions between these four molecules and the surface. However, the Zn vacancy on the surface can significantly elevate the chemical interactions between SO₂/H₂S and the surface. The two-coordinated O atom (O_2c) on the surface plays an important role. For SO₂ and H₂S adsorption, the S atom in SO₂ or H₂S tends to bond to the O_2c atom, bringing much larger adsorption energy compared to the adsorption over the perfect ZnO(101̅0) surface. This work can provide a basis for surface modification of ZnO in applications to detecting SF₆ decomposed products by theoretical evaluation.

SUBMITTER: Chen D

PROVIDER: S-EPMC6643918 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Adsorption of SF6 Decomposed Products on ZnO-Modified C3N: A Theoretical Study.

Project description:SF6, as an outstanding insulation medium, is widely used in the high-voltage insulation devices, guaranteeing the safe operation of the power system. Nevertheless, the inevitable partial discharge in a long-running device causes the decomposition of SF6 and deteriorates its insulation performance. In this work, DFT calculations were performed to study the adsorbing and sensing properties of ZnO-modified C3N (ZnO-C3N) nanosheet towards SF6 decomposed products, in order to propose a novel nano-candidate for evaluating the operation status of SF6 insulation devises. We first investigated the structure of ZnO-C3N monolayer and then simulated its adsorption behaviour upon four typical SF6 decomposed species, namely H2S, SO2, SOF2, and SO2F2. It is found that the ZnO-C3N monolayer can exhibit desirable reactivity and sensitivity on SO2, SOF2, and SO2F2, leading to the intense deformation of gas molecules and large adsorption energies. These consequences allow the potential application of gas adsorbent based on ZnO-C3N monolayer for removing impurity gases from SF6 insulation equipment. According to the analysis, it is supposed that ZnO-C3N monolayer is qualified to be used in maintaining insulation strength and ensuring the safe operation of power system.

| S-EPMC7519028 | biostudies-literature

Adsorption Behavior of Ni-Doped ZnO Monolayer upon SF6 Decomposed Components and Effect of the Applied Electric Field.

Project description:In this article, Ni-doped ZnO (Ni-ZnO) monolayer is proposed as a potential sensing material for detection of two SF6 decomposed components (namely, SO2 and SOF2), based on the density functional theory (DFT) method, to monitor the operation status of SF6 insulation devices in the power system. The Ni-doping effect on the physicochemical properties of the pure ZnO monolayer is first studied, with the binding energy (E b) calculated as -1.49 eV. Then, the adsorption of a Ni-ZnO monolayer upon SO2 and SOF2 molecules shows that the Ni-ZnO monolayer exhibits strong chemisorption upon the two gas species, with the adsorption energy (E ad) obtained as -2.38 and -2.19 eV, respectively. The electronic properties of the Ni-ZnO monolayer upon gas adsorption are studied through the density-of-state (DOS) analysis, whereas the band structure (BS) and work function (WF) analysis provide the sensing mechanism of the Ni-ZnO monolayer upon two gases. In addition, the charge-transfer behavior during adsorption in the applied electric fields is analyzed to expound the possibility of Ni-ZnO monolayer as a field-effect-transistor gas sensor. Our calculations can stimulate the study on adsorption and sensing behaviors of TM-ZnO monolayers for their applications in many fields.

| S-EPMC7513549 | biostudies-literature

Photoelectrochemical CO2 Reduction Products Over Sandwiched Hybrid Ga2O3:ZnO/Indium/ZnO Nanorods.

Project description:Recycled valuable energy production by the electrochemical CO2 reduction method has explosively researched using countless amounts of developed electrocatalysts. Herein, we have developed hybrid sandwiched Ga2O3:ZnO/indium/ZnO nanorods (GZO/In/ZnONR) and tested their photoelectrocatalytic CO2 reduction performances. Gas chromatography and nuclear magnetic spectroscopy were employed to examine gas and liquid CO2 reduction products, respectively. Major products were observed to be CO, H2, and formate whose Faradaic efficiencies were highly dependent on the relative amounts of overlayer GZO and In spacer, as well as applied potential and light irradiation. Overall, the present study provides a new strategy of controlling CO2 reduction products by developing a sandwiched hybrid catalyst system for energy and environment.

| S-EPMC8863927 | biostudies-literature

Formation and evolution of orientation-specific CO2 chains on nonpolar ZnO(1010) surfaces.

Project description:Clarifying the fundamental adsorption and diffusion process of CO2 on single crystal ZnO surfaces is critical in understanding CO2 activation and transformation over ZnO-based catalysts. By using ultrahigh vacuum-Fourier transform infrared spectroscopy (UHV-FTIRS), we observed the fine structures of CO2 vibrational bands on ZnO(100) surfaces, which are the combinations of different vibrational frequencies, originated from CO2 monomer, dimer, trimer and longer polymer chains along [0001] direction according to the density functional theory calculations. Such novel chain adsorption mode results from the relatively large attractive interaction between CO2 and Zn3c atoms in [0001] direction. Further experiments indicate that the short chains at low coverage evolve into long chains through Ostwald ripening by annealing. At higher CO2 coverage (0.7?ML), the as-grown local (2?×?1) phase of chains first evolve into an unstable local (1?×?1) phase below 150?K, and then into a stable well-defined (2?×?1) phase above 150?K.

| S-EPMC5473178 | biostudies-literature

Oxygen Adsorption on Polar and Non-Polar Zn:ZnO Heterostructures from First Principles.

Project description:Zn:ZnO nanostructures have been studied extensively due to their potential use in many applications, such as oxygen scavengers for food packaging applications. Under atmospheric conditions, ZnO grows on the surface of Zn via an oxidation process. The mechanisms governing Zn oxidation are still not fully understood, with classical oxidation models, such as the Cabrera Mott, underestimating the oxide thickness of Zn:ZnO core-shell structures. In this work, Ab initio DFT calculations were performed to assess the adsorption properties of oxygen molecules on Zn:ZnO heterostructures to help elucidate the mechanisms involved in the growth of a ZnO film on a Zn substrate. Results suggest that the charge transfer mechanism from the Zn:ZnO heterostructures to the adsorbed oxygen layer can be promoted by two different processes: the electronic doping of ZnO due to the formation of the Zn:ZnO interface and the excess surface charge due to the presence of dangling bonds on the as cleaved ZnO.

| S-EPMC9919104 | biostudies-literature

Rh-doped MoTe2 Monolayer as a Promising Candidate for Sensing and Scavenging SF6 Decomposed Species: a DFT Study.

Project description:In this work, the adsorption and sensing behaviors of Rh-doped MoTe2 (Rh-MoTe2) monolayer upon SO2, SOF2, and SO2F2 are investigated using first-principles theory, wherein the Rh doping behavior on the pure MoTe2 surface is included as well. Results indicate that TMo is the preferred Rh doping site with Eb of - 2.69 eV, and on the Rh-MoTe2 surface, SO2 and SO2F2 are identified as chemisorption with Ead of - 2.12 and - 1.65 eV, respectively, while SOF2 is physically adsorbed with Ead of - 0.46 eV. The DOS analysis verifies the adsorption performance and illustrates the electronic behavior of Rh doping on gas adsorption. Band structure and frontier molecular orbital analysis provide the basic sensing mechanism of Rh-MoTe2 monolayer as a resistance-type sensor. The recovery behavior supports the potential of Rh-doped surface as a reusable SO2 sensor and suggests its exploration as a gas scavenger for removal of SO2F2 in SF6 insulation devices. The dielectric function manifests that Rh-MoTe2 monolayer is a promising optical sensor for selective detection of three gases. This work is beneficial to explore Rh-MoTe2 monolayer as a sensing material or a gas adsorbent to guarantee the safe operation of SF6 insulation devices in an easy and high-efficiency manner.

| S-EPMC7295872 | biostudies-literature

Theoretical Study on Adsorption Behavior of SF6 Decomposition Components on Mg-MOF-74.

Project description:SF6 gas is an arc extinguishing medium that is widely used in gas insulated switchgear (GIS). When insulation failure occurs in GIS, it leads to the decomposition of SF6 in partial discharge (PD) and other environments. The detection of the main decomposition components of SF6 is an effective method to diagnose the type and degree of discharge fault. In this paper, Mg-MOF-74 is proposed as a gas sensing nanomaterial for detecting the main decomposition components of SF6. The adsorption of SF6, CF4, CS2, H2S, SO2, SO2F2 and SOF2 on Mg-MOF-74 was calculated by Gaussian16 simulation software based on density functional theory. The analysis includes parameters of the adsorption process such as binding energy, charge transfer, and adsorption distance, as well as the change in bond length, bond angle, density of states, and frontier orbital of the gas molecules. The results show that Mg-MOF-74 has different degrees of adsorption for seven gases, and chemical adsorption will lead to changes in the conductivity of the system; therefore, it can be used as a gas sensing material for the preparation of SF6 decomposition component gas sensors.

| S-EPMC10254539 | biostudies-literature

Theoretical insights into the generation and reactivity of hydride on the ZnO(1010) surface.

Project description:ZnO is an important catalytic material for CO/CO2 hydrogenation. In this work, the pristine ZnO(101̄0) and the surfaces with Zn-O dimer vacancies (ZnO(101̄0)-(Zn-O)DiV) and oxygen vacancies are calculated. We find that the hydride (H-) species can be generated via heterolytic H2 dissociation on these surfaces, and that ZnO(101̄0)-(Zn-O)DiV only needs to overcome the energy barrier of ∼0.10 eV. This is because the ZnO system has flexible orbitals for electron storage and release and the low-coordinated Zn3c atoms at the defect sites can form stable Zn-H- covalent bonds with high symmetry. Flexible Zn orbitals also impart the unique feature of activating multiple electrophilic adsorbates simultaneously as excess electrons exist. Moreover, we show that the covalent Zn-H- species can regulate the catalytic activity and selectivity for CO2 hydrogenation by preferentially producing *HCOO intermediates at Zn-O dimer vacancies. These results may help in the design of efficient Zn-based hydrogenation catalysts.

| S-EPMC11351784 | biostudies-literature

Reactivity of Xantphos-Type Rhodium Complexes Towards SF4 : SF3 Versus SF2 Complex Generation.

Project description:S-F-bond activation of sulfur tetrafluoride at [Rh(Cl)(tBu xanPOP)] (1; tBu xanPOP=9,9-dimethyl-4,5-bis-(di-tert-butylphosphino)-xanthene) led to the formation of the cationic complex [Rh(F)(Cl)(SF2 )(tBu xanPOP)][SF5 ] (2 a) together with trans-[Rh(Cl)(F)2 (tBu xanPOP)] (3) and cis-[Rh(Cl)2 (F)(tBu xanPOP)] (4) which both could also be obtained by the reaction of SF5 Cl with 1. In contrast to that, the conversion of SF4 at the methyl complex [Rh(Me)(tBu xanPOP)] (5) gave the isolable and room-temperature stable cationic λ4 -trifluorosulfanyl complex [Rh(Me)(SF3 )(tBu xanPOP)][SF5 ] (6). Treatment of 6 with the Lewis acids BF3 or AsF5 produced the dicationic difluorosulfanyl complex [Rh(Me)(SF2 )(tBu xanPOP)][BF4 ]2 (8 a) or [Rh(Me)(SF2 )(tBu xanPOP)][AsF6 ]2 (8 b), respectively. Refluorination of 8 a was possible with the use of dimethylamine giving [Rh(Me)(SF3 )(tBu xanPOP)][BF4 ] (9). A reaction of 6 with trichloroisocyanuric acid (TClCA) gave the fluorido complex [Rh(F)(Cl)(SF2 )(tBu xanPOP)][Cl] (2 b) together with chloromethane and SF5 Cl.

| S-EPMC9322540 | biostudies-literature

Formaldehyde Molecules Adsorption on Zn Doped Monolayer MoS2: A First-Principles Calculation.

Project description:Based on the first principles of density functional theory, the adsorption behavior of H2CO on original monolayer MoS2 and Zn doped monolayer MoS2 was studied. The results show that the adsorption of H2CO on the original monolayer MoS2 is very weak, and the electronic structure of the substrate changes little after adsorption. A new kind of surface single cluster catalyst was formed after Zn doped monolayer MoS2, where the ZnMo3 small clusters made the surface have high selectivity. The adsorption behavior of H2CO on Zn doped monolayer MoS2 can be divided into two situations. When the H-end of H2CO molecule in the adsorption structure is downward, the adsorption energy is only 0.11 and 0.15 eV and the electronic structure of adsorbed substrate changes smaller. When the O-end of H2CO molecule is downward, the interaction between H2CO and the doped MoS2 is strong leading to the chemical adsorption with the adsorption energy of 0.80 and 0.98 eV. For the O-end-down structure, the adsorption obviously introduces new impurity states into the band gap or results in the redistribution of the original impurity states. All of these may lead to the change of the chemical properties of the doped MoS2 monolayer, which can be used to detect the adsorbed H2CO molecules. The results show that the introduction of appropriate dopant may be a feasible method to improve the performance of MoS2 gas sensor.

| S-EPMC8085485 | biostudies-literature