Adsorption of metal atoms on silicene: stability and quantum capacitance of silicene-based electrode materials

2019 ◽  
Vol 21 (8) ◽  
pp. 4276-4285 ◽  
Author(s):  
Q. Xu ◽  
G. M. Yang ◽  
Xiaofeng Fan ◽  
W. T. Zheng
Keyword(s):  
Electrode Materials ◽  
Quantum Capacitance ◽  
Metal Doping ◽  
Vacancy Complex ◽  
Metal Atoms ◽  
Metal Vacancy

Metal-doping with the formation of a metal–vacancy complex results in an obvious increase of silicene's quantum capacitance.

scholarly journals DFT calculation for the electronic properties and quantum capacitance of pure and doped Zr2CO2 as electrode of supercapacitors

2021 ◽  
Author(s):  
Shuo Xu ◽  
Shi-Jie Wang ◽  
Li Xiao-Hong ◽  
Hong-Ling Cui
Keyword(s):  
Electronic Properties ◽  
Electrode Materials ◽  
Chemical Properties ◽  
Effect Of Temperature ◽  
Quantum Capacitance ◽  
Substitutional Site ◽  
Level Shifts ◽  
Dirac Distribution ◽  
Increasing Temperature ◽  
Physical And Chemical

Defect and doping are effective methods to modulate the physical and chemical properties of materials. In this report, we investigated the structural stability, electronic properties and quantum capacitance (Cdiff) of Zr2CO2 by changing the dopants of Si, Ge, Sn, N, B, S and F in the substitutional site. The doping of F, N, and S atoms makes the system undergo the semiconductor-to-conductor transition, while the doping of Si, Ge, and Sn maintains the semiconductor characteristics. The Cdiff of the doped systems are further explored. The B-doped system can be used as cathode materials, while the systems doped by S, F, N, Sn atoms are promising anode materials of asymmetric supercapacitors, especially for the S-doped system. The improved Cdiff mainly originates from Fermi-level shifts and Fermi-Dirac distribution by the introduction of the dopant. The effect of temperature on Cdiff is further explored. The result indicates that the maximum Cdiff of the studied systems gradually decreases with the increasing temperature. Our investigation can provide useful theoretical basis for designing and developing the ideal electrode materials for supercapacitors.

Computational exploration of borophane-supported single transition metal atoms as potential oxygen reduction and evolution electrocatalysts

2018 ◽  
Vol 20 (32) ◽  
pp. 21095-21104 ◽  
Author(s):  
Yashpal Singh ◽  
Seoin Back ◽  
Yousung Jung
Keyword(s):  
Transition Metal ◽  
Oxygen Reduction ◽  
Surface Activation ◽  
Transition Metal Doping ◽  
Metal Doping ◽  
Metal Atoms ◽  
Transition Metal Atoms ◽  
Computational Exploration ◽  
Single Transition ◽  
Potential Oxygen

Surface activation of 2D borophane for oxygen reduction and evolution reactions is demonstrated with the help of substitutional transition metal doping.

scholarly journals Recent Advances in the Electrocatalytic Application of Transition Metal Nitrides Nanocrystalline

2021 ◽  
Author(s):  
Haolin Tang ◽  
Shuhong Zheng ◽  
Ren Luo
Keyword(s):  
Transition Metal ◽  
Noble Metals ◽  
Electrode Materials ◽  
Precious Metals ◽  
High Energy ◽  
High Energy Density ◽  
Energy Storage And Conversion ◽  
Metal Nitrides ◽  
Transition Metal Nitrides ◽  
Metal Atoms

The energy crisis and environmental problems are becoming more and more severe due to the long-term consumption of fossil fuels. Therefore, energy conversion devices with high energy density and environmental friendliness (such as fuel cells, metal-air batteries, etc.) have been ex-pected to be reliable alternatives to traditional fossil energy. However, due to the inevitable use of precious metals as the electrode catalysts for these devices, the popularization of these alternatives is seriously hindered. Transition metal nitrides (TMNs) exhibit similar surface and adsorption properties to noble metals since the atomic distance between metal atoms increases and the d-band center of metal atoms downshift after the nitrogen atoms enter the metal lattice. TMNs have become one of the best electrode materials to replace noble metal electrocatalysts in energy storage and conversion devices. In this review, the latest development in the electrocatalytic ap-plication of TMNs nanocrystalline is covered. Firstly, we briefly discuss the structure and activity origin of TMNs and introduce the common physical and chemical methods for the preparation of TMNs. Subsequently, we illustrate the applications of unary TMNs and multivariate TMNs in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Finally, we summarize the challenges and problems of TMNs encountered at the present stage, and expect its future de-velopment.

Structural transformations in boron clusters induced by metal doping

2022 ◽  
Author(s):  
Jorge Barroso ◽  
Sudip Pan ◽  
Gabriel Merino
Keyword(s):  
Structural Transformation ◽  
Structural Transformations ◽  
Metal Doping ◽  
Boron Clusters ◽  
Metal Atoms

Would it be possible to eventually derive a simple methodology to predict the structure adopted by boron clusters based on its structural transformation induced by the doping with one or two metal atoms?

scholarly journals First-Principles Density Functional Theory Study of Modified Germanene-Based Electrode Materials

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 103
Author(s):  
Xue Si ◽  
Weihan She ◽  
Qiang Xu ◽  
Guangmin Yang ◽  
Zhuo Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Electrode Materials ◽  
Layer Structure ◽  
Localized States ◽  
First Principles Calculation ◽  
Quantum Capacitance ◽  
Multilayered Structures ◽  
Functional Theory

Germanene, with a wrinkled atomic layer structure and high specific surface area, showed high potential as an electrode material for supercapacitors. According to the first-principles calculation based on Density Functional Theory, the quantum capacitance of germanene could be significantly improved by introducing doping/co-doping, vacancy defects and multilayered structures. The quantum capacitance obtained enhancement as a result of the generation of localized states near the Dirac point and/or the movement of the Fermi level induced by doping and/or defects. In addition, it was found that the quantum capacitance enhanced monotonically with the increase of the defect concentration.

CO oxidation on SnO2 surfaces enhanced by metal doping

2018 ◽  
Vol 8 (3) ◽  
pp. 782-789 ◽  
Author(s):  
Junemin Bae ◽  
Jiwhan Kim ◽  
Hojin Jeong ◽  
Hyunjoo Lee
Keyword(s):  
Catalytic Activity ◽  
Metal Oxide ◽  
Co Oxidation ◽  
Surface Oxygen ◽  
Metal Doping ◽  
Metal Atoms ◽  
Host Metal

Doping metal atoms into a host metal oxide lattice can enhance its catalytic activity by modulating the properties of surface oxygen.

Incommensurate modulated phases of the NbxTa1-xTe4 charge density wave system

1992 ◽  
Vol 50 (1) ◽  
pp. 58-59
Author(s):  
S. Ritchie ◽  
J. C. Bennett ◽  
A. Prodan ◽  
F.W. Boswell ◽  
J.M. Corbett
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Direct Evidence ◽  
Density Wave ◽  
Wave System ◽  
Modulated Phases ◽  
Metal Atoms ◽  
Incommensurate Modulation ◽  
End Members ◽  
Modulation Wave Vector

A continuous sequence of compounds having composition NbxTa1-xTe4; 0 ≤ x ≤ 1 have been studied by electron diffraction and microscopy. Previous studies have shown that the end members of the series, TaTε4 and NbTε4 possess a quasi-one-dimensional character and exhibit charge density wave (CDW) distortions. In these compounds, the subcell structure is tetragonal with axes (a × a × c) and consists of the metal atoms (Nb or Ta) centered within an extended antiprismatic cage of Te atoms. At room temperature, TaTε4 has a commensurate modulation structure with a 2a × 2a × 3c unit cell. In NbTε4, an incommensurate modulation with × ∼ 16c axes is observed. Preliminary studies of the mixed compounds NbxTα1-xTε4 showed a discontinuous jump of the modulation wave vector commensurate to incommensurate when the Nb dopant concentration x, exceeded x ≃ 0.3, In this paper, the nature of the compositional dependence of is studied in greater detail and evidence is presented for a stepwise variation of . This constitutes the first direct evidence for a Devil's staircase in CDW materials.

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