scholarly journals Influences of MgO(001) and TiO2(101) Supports on the Structures and Properties of Au Nanoclusters

Catalysts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 16
Author(s):  
Jinhua Gao ◽  
Yuehong Ren ◽  
Qingzhen Han ◽  
Hao Wen ◽  
Zhaotan Jiang
Keyword(s):  
Electronic Structure ◽  
Catalytic Activity ◽  
Density Functional ◽  
Gold Nanoclusters ◽  
Reduction Reaction ◽  
Surface Charges ◽  
Photoelectric Properties ◽  
Structures And Properties ◽  
Potential Applications ◽  
The Difference

Due to the unique structures, photoelectric properties, good catalytic activity, and broad potential applications, gold nanoclusters (Au n ) received extensive attention in catalysis, bioengineering, environmental engineering, and so on. In the present work, the structures and properties of Au n adsorbed on the MgO(001) and TiO 2 (101) surfaces were investigated by density functional theory. The results showed that the catalytic properties of Au n will be enhanced when Au n is adsorbed on certain supports. Because the difference of the outer electronic structure of metals in supports, the direction of the charge transfer was different, thus inducing the different charge distribution on Au n . When Au n was adsorbed on MgO(001) [TiO 2 (101)] surface, Au n will have negative [positive] charges and thus higher catalytic activity in oxidation [reduction] reaction. The variation of surface charges caused by the support makes Au n possess different catalytic activity in different systems. Moreover, the electronic structure of the support will make an obvious influence on the s and d density of states of Au n , which should be the intrinsic reason that induces the variations of its structure and properties. These results should be an important theoretical reference for designing Au n as the photocatalyst applied to the different oxidation and reduction reactions.

A systematic computational investigations of water splitting and N2 reduction reaction performances of monolayer MBenes

2021 ◽  
Author(s):  
Yuwen Cheng ◽  
Jisheng Mo ◽  
Yongtao Li ◽  
Yan Song ◽  
Yumin Zhang
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Water Splitting ◽  
Density Functional ◽  
Reduction Reaction ◽  
Functional Theory ◽  
Energy Conversion And Storage ◽  
Metal Borides ◽  
Potential Applications ◽  
And Storage

Recently, transition metal borides (MBenes, analogous to MXenes) have been attracted interest due to their potential applications in energy conversion and storage. In this work, we performed density functional theory...

scholarly journals Theoretical design of a technetium-like alloy and its catalytic properties

2019 ◽  
Vol 10 (21) ◽  
pp. 5461-5469
Author(s):  
Wei Xie ◽  
Michihisa Koyama
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Catalytic Activity ◽  
Density Of States ◽  
Phase Stability ◽  
Density Functional ◽  
Catalytic Properties ◽  
Functional Theory ◽  
Theoretical Design ◽  
Structure Phase

Based on the concept of density of states (DOS) engineering, we theoretically designed a pseudo-Tc material (Mo–Ru alloy) and investigated its electronic structure, phase stability and catalytic activity by using density functional theory.

Oxygen reduction reaction mechanism on P, N co-doped graphene: a density functional theory study

2019 ◽  
Vol 43 (48) ◽  
pp. 19308-19317 ◽  
Author(s):  
Zhao Liang ◽  
Chao Liu ◽  
Mingwei Chen ◽  
Xiaopeng Qi ◽  
Pramod Kumar U. ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Catalytic Activity ◽  
Reaction Mechanism ◽  
Dft Calculations ◽  
Density Functional ◽  
Reduction Reaction ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Doped Graphene ◽  
Co Doped

DFT calculations confirmed that the P–N coupled site changed the ORR pathway and improved the catalytic activity compared with single doping.

Substrate Polarity Effects on the Interface Electronic Structure in Organic Light Emitting Diodes

2016 ◽  
Vol 852 ◽  
pp. 746-749
Author(s):  
Huang Tian ◽  
Xin Zhao ◽  
Qiang Zhang ◽  
Huai Xin Wei
Keyword(s):  
Electronic Structure ◽  
Performance Enhancement ◽  
Open Circuit ◽  
Organic Electronic Devices ◽  
Light Emitting ◽  
Organic Layers ◽  
Interface Dipole ◽  
Potential Applications ◽  
The Difference ◽  
Polarity Effects

Organic layers deposited on various polarity substrates and the electronic structures of (PTCDA/TiOPc) on hydrophobic and hydrophilic substrates have been studied by ultraviolet photoemission spectroscopy. The difference between work function and polarity of the substrates induce the formation of an interface dipole with corresponding shift in the relative position of molecular levels across the interface. While the vacuum level and open circuit voltage show vastly difference respectively, the barrier between anode-organic or organic-cathode also changes from 0.75eV to 1.13eV or 0.35eV to 0.65eV. The results show the possibility of tuning the electronic structure by the modification of substrate and potential applications on performance enhancement in organic electronic devices.

Reactivity of boron- and nitrogen-doped carbon nanotubes functionalized by (Pt, Eu) atoms toward O2 and CO: A density functional study

2016 ◽  
Vol 27 (07) ◽  
pp. 1650075 ◽  
Author(s):  
S. Abdel Aal
Keyword(s):  
Catalytic Activity ◽  
Charge Transfer ◽  
Density Functional ◽  
Co Adsorption ◽  
Energy Charge ◽  
Reduction Reaction ◽  
Functional Study ◽  
High Catalytic Activity ◽  
N Doping ◽  
Different Response

The adsorption behavior and electronic properties of CO and O2 molecules at the supported Pt and Eu atoms on (5,5) armchair SWCNT have been systematically investigated within density functional theory (DFT). Fundamental aspects such as adsorption energy, natural bond orbital (NBO), charge transfer, frontier orbitals and the projected density of states (PDOS) are elucidated to analyze the adsorption properties of CO and O2 molecules. The results reveal that B- and N-doping CNTs can enhance the binding strength and catalytic activity of Pt (Eu) anchored on the doped-CNT, where boron-doping is more effective. The electronic structures of supported metal are strongly influenced by the presence of gases. After adsorption of CO and O2, the changes in binding energy, charge transfer and conductance may lead to the different response in the metal-doped CNT-based sensors. It is expected that these results could provide helpful information for the design and fabrication of the CO and O2 sensing devices. The high catalytic activity of Pt supported at doped-CNT toward the interaction with CO and O2 may be attributed to the electronic resonance particularly among Pt-5d, CO-2[Formula: see text]* and O2-2[Formula: see text]* antibonding orbitals. In contrast to the supported Eu at doped-CNT, the Eu atom becomes more positively charged, which leads to weaken the CO adsorption and promote the O2 adsorption, consequently enhancing the activity for CO oxidation and alleviating the CO poisoning of the europium catalysts. A notable orbital hybridization and electrostatic interaction between these two species in adsorption process being an evidence of strong interaction. The electronic structure of O2 adsorbed on Eu-doped CNT resembles that of O[Formula: see text], therefore the transferred charge weakens the O–O bonds and facilitates the dissociation process, which is the precondition for the oxygen reduction reaction (ORR).

Electronic structure and phase stability of In-free photovoltaic semiconductors, Cu2ZnSnSe4 and Cu2ZnSnS4 by first-principles calculation

2009 ◽  
Vol 1165 ◽  
Author(s):  
Tsuyoshi Maeda ◽  
Satoshi Nakamura ◽  
Takahiro Wada
Keyword(s):  
Electronic Structure ◽  
Plane Wave ◽  
Phase Stability ◽  
First Principles ◽  
Density Functional ◽  
Formation Enthalpy ◽  
First Principles Calculation ◽  
Enthalpies Of Formation ◽  
Functional Formalism ◽  
The Difference

AbstractWe have theoretically evaluated the phase stability and electronic structure of Cu2ZnSnSe4 (CZTSe) and Cu2ZnSnS4 (CZTS). The enthalpies of formation for kesterite, stannite and wurtz-stannite phases of CZTSe and CZTS were calculated using a plane-wave pseudopotential method within the density functional formalism. For CZTSe, the calculated formation enthalpy (ΔH) of the kesterite phase (−312.7 kJ/mol) is a little smaller than that of the stannite phase (−311.3 kJ/mol) and much smaller than that of the wurtz-stannite phase (−305.7 kJ/mol). For CZTS, the ΔH of the kesterite phase (−361.9 kJ/mol) is smaller than that of the stannite phase (−359.9 kJ/mol) and much smaller than that of the wurtz-stannite phase (−354.6 kJ/mol). The difference of ΔH between the kesterite and stannite phases for CZTS is greater than that for CZTSe. This indicates the kesterite phase is more stable than the stannite phase in CZTS compared with CZTSe. The valence band maximums (VBMs) of both the kesterite- and stannite-type CZTSe(CZTS) are antibonding orbitals of Cu 3d and Se 4p (S 3p). The conduction band minimums (CBMs) are antibonding orbitals of Sn 5s and Se 4p (S 3p). The Zn atom does not affect the VBM or the CBM in either CZTSe(CZTS). The theoretical band gap of the kesterite phase calculated with sX-LDA in both CZTSe and CZTS is a little wider than that of the wurtz-stannite phase and much wider than that of the stannite phase.

Photoelectric Response Difference between KTaO3/ Au and K2Ta2O6/Au Nanocrystals Resulting from Potassium Tantalate Structure

2019 ◽  
Vol 814 ◽  
pp. 83-89
Author(s):  
Sheng Ding Chang ◽  
Mu Wei Ji ◽  
Chang Xu Yan ◽  
Bo Li ◽  
Jin Wang
Keyword(s):  
Light Absorption ◽  
Au Nanoparticles ◽  
Photoelectric Property ◽  
Potassium Tantalate ◽  
Multiple Factors ◽  
Photoelectric Response ◽  
Photoelectric Properties ◽  
Potential Applications ◽  
The Difference

Potassium tantalates is one kind of important semiconductor with potential applications on photoelectric transformation and photocatalysis. Herein, Au nanoparticles were grown on the surface of two kinds of potassium tantalates, KTaO3 nanocubes and K2Ta2O6 nanooctahedron, by flexible reducing HAuCl4, and KTaO3/Au and K2Ta2O6/Au hetero-nanostructures were formed. Although the Au nanoparticles loading enhances the light absorption, KTaO3/Au and K2Ta2O6/Au hetero-nanostructures exhibit different photoelectric properties. The difference of photoelectric properties of two kinds of potassium tantalates/Au hetero-structures hint the photoelectric-property enhancement depends on multiple factors.

A comparative study of hydrogen evolution reaction on pseudo-monolayer WS2 and PtS2: insights based on the density functional theory

2017 ◽  
Vol 7 (3) ◽  
pp. 687-692 ◽  
Author(s):  
Showkat H. Mir ◽  
Sudip Chakraborty ◽  
John Wärnå ◽  
Som Narayan ◽  
Prakash C. Jha ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Density Functional ◽  
Electronic Structure Calculations ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structure Calculations

In this study, we investigated the catalytic activity of ultrathin PtS2 and WS2 nanostructures for the hydrogen evolution reaction by electronic structure calculations based on the spin-polarised density functional theory.

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