The Influence of Alkaline Earth Elements on Electronic Properties of α-Si3N4 via DFT Calculation

Zhang, Jianwen; Huang, Zhifeng; Yin, Ziqian; Li, Meijuan; Shen, Qiang

doi:10.1007/s11595-020-2331-4

Cited by 5 publications

(3 citation statements)

References 52 publications

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“…Density functional theory (DFT) adopts the Vienna ab-initio simulation package (VASP). The Projection Enhanced Wave (PAW) method utilizes the interaction between electrons and the core, and it uses Generalized Gradient Approximation (GGA) and Perdew Burke Ernzerhof (PBE) functions to achieve electron exchange correlation [24]. In the process of geometric optimization, the convergence achieved at the energy difference is 10 −5 eV, with an ion relaxation convergence standard of 0.05 eV/Å.…”

Section: Computational Modeling and Methodologymentioning

confidence: 99%

Mechanistic Insight into the Propane Oxidation Dehydrogenation by N2O over Cu-BEA Zeolite with Diverse Active Site Structures

Liu

Dai

et al. 2023

Catalysts

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The present work theoretically investigated propane oxidation dehydrogenation by utilizing N2O as an oxidant (N2O-ODHP) over Cu-BEA with three different types of active site, including monomeric Cu ([Cu]+), dimeric Cu ([Cu−Cu]2+), and distant monomeric Cu sites ([Cu]+—[Cu]+). Energetically, we calculated that the monomeric [Cu]+ is favorable for the αH dehydrogenation step (∆E = 0.05 eV), which, however, suffers from high barriers of N2O dissociation and βH dehydrogenation steps of 1.40 and 1.94 eV, respectively. Although the dimeric [Cu−Cu]2+ site with a Cu—Cu distance of 4.91 Å is much more favorable for N2O dissociation (0.95 eV), it still needs to overcome an extremely high barrier (∆E = 2.15 eV) for βH dehydrogenation. Interestingly, the distant [Cu]+—[Cu]+ site with the Cu—Cu distance of 5.82 Å exhibits low energy barriers for N2O dissociation (0.89 eV) and ODHP steps (0.01 and 0.33 eV) due to the synergistic effect of distant [Cu]+. The microkinetic analyses quantitatively verified the superior activity of the distant [Cu]+—[Cu]+ site with a reaction rate being eight to nine orders of magnitude higher than those of the monomeric and the dimeric Cu sites, and this is related to its ready charge-transfer ability, as shown by the partial Density of State (PDOS) analysis and the static charge differential density analysis in this study. Generally, the present work proposes that the distance between the [Cu]+ sites plays a significant and important role in N2O-ODHP over the Cu-based zeolite catalyst and modulates Cu—Cu distance, and this constitutes a promising strategy for highly-efficient Cu-zeolite catalyst design for N2O-ODHP.

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Section: Computational Modeling and Methodologymentioning

confidence: 99%

Mechanistic Insight into the Propane Oxidation Dehydrogenation by N2O over Cu-BEA Zeolite with Diverse Active Site Structures

Liu

Dai

et al. 2023

Catalysts

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“…With the same HSE06 method, the bandgap is higher than those of the similarly structured MoSi 2 N 4 monolayer (2.297 eV), 14 MA 2 N 4 (0.99-3.25 eV), 24 MoS 2 (2.23 eV), 71 and phosphorene (1.58 eV), 72 but is closer to that of the h-BN monolayer (5.56 eV). 70 With the same PBE method, its bandgap of 3.865 eV is less than α-Si 3 N 4 (4.68 eV) 73 and β-Si 3 N 4 (4.3 eV), 74 and much higher than SL Si 3 N 4 (about 2 eV). 52 The contribution to the VBM and CBM for each atom in Si 3 N 4 can be visualized by the partial charge density (PCD) distribution, as shown in Fig.…”

Section: Tunable Electronic Propertiesmentioning

confidence: 96%

Two-dimensional superhard silicon nitrides with widely tunable bandgap, high carrier mobility and hole-doping-induced robust magnetism

Ma,

Jiang,

Zou

et al. 2023

Nanoscale

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“…[ 26 ] In situ alloying from elemental powder by AM is a cost‐effective alternative, which provides the flexibility of atomic ratio of alloy. [ 27,28 ] This is an effective method to control material properties or create new alloys, especially for NiTi alloys whose phase transition temperature is highly sensitive to composition. [ 26,28,29 ] The atomic ratio difference between Ni and Ti would have a significant impact on the phase transition behavior and microstructure of NiTi.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Behavior and Shape‐Memory Effects of Ni_xTi_1−x Alloys with Tunable Mixing of Ni/Ti Powders by Laser‐Directed Energy Deposition

Lu,

Qiu,

Liu

et al. 2024

Adv Eng Mater

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As we know, controlling NiTi alloy’s microstructure is an urgent problem in additive manufacturing, which directly affects the mechanical properties of the alloy. In laser directed energy deposition (LDED) technology, the simultaneous powder feeding equipment with double powder barrels can effectively control the material ratio and realize the generation of NixTi1‐x alloys with different atomic ratios. Firstly, the performance differences of NiTi alloy under different thermal treatments are explored. Based on this, the optimal thermal treatment process is used to adjust the microstructure of NiTi alloy fabricated by laser directed energy deposition by changing the Ni/Ti atomic ratio to improve mechanical properties. The results indicate that Ni4Ti3 precipitates could induce the R phase, change the phase transition, and improve the mechanical properties in Ni‐rich NiTi alloys. Besides, the mechanical properties of NixTi1‐x alloy can be enhanced by adjusting the Ni/Ti atomic ratio to change the content of Ni4Ti3 precipitates. Ni52Ti48 alloy has a tensile strength of 771 MPa, an elongation of 11.6 %, and a recovery rate of 95.2%.This article is protected by copyright. All rights reserved.

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The Influence of Alkaline Earth Elements on Electronic Properties of α-Si3N4 via DFT Calculation

Cited by 5 publications

References 52 publications

Mechanistic Insight into the Propane Oxidation Dehydrogenation by N2O over Cu-BEA Zeolite with Diverse Active Site Structures

Mechanistic Insight into the Propane Oxidation Dehydrogenation by N2O over Cu-BEA Zeolite with Diverse Active Site Structures

Two-dimensional superhard silicon nitrides with widely tunable bandgap, high carrier mobility and hole-doping-induced robust magnetism

Mechanical Behavior and Shape‐Memory Effects of Ni_xTi_1−x Alloys with Tunable Mixing of Ni/Ti Powders by Laser‐Directed Energy Deposition

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The Influence of Alkaline Earth Elements on Electronic Properties of α-Si3N4 via DFT Calculation

Cited by 5 publications

References 52 publications

Mechanistic Insight into the Propane Oxidation Dehydrogenation by N2O over Cu-BEA Zeolite with Diverse Active Site Structures

Mechanistic Insight into the Propane Oxidation Dehydrogenation by N2O over Cu-BEA Zeolite with Diverse Active Site Structures

Two-dimensional superhard silicon nitrides with widely tunable bandgap, high carrier mobility and hole-doping-induced robust magnetism

Mechanical Behavior and Shape‐Memory Effects of NixTi1−x Alloys with Tunable Mixing of Ni/Ti Powders by Laser‐Directed Energy Deposition

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Product

Resources

About

Mechanical Behavior and Shape‐Memory Effects of Ni_xTi_1−x Alloys with Tunable Mixing of Ni/Ti Powders by Laser‐Directed Energy Deposition