scholarly journals Hole-Phonon Relaxation and Photocatalytic Properties of Titanium Dioxide and Zinc Oxide: First-Principles Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
V. P. Zhukov ◽  
V. G. Tyuterev ◽  
E. V. Chulkov ◽  
P. M. Echenique
Keyword(s):  
Zinc Oxide ◽  
Titanium Dioxide ◽  
Distribution Function ◽  
Photocatalytic Activity ◽  
Valence Band ◽  
First Principles ◽  
Spectral Dependence ◽  
First Principles Calculations ◽  
Oxidative Reactions ◽  
Analogous Data

First-principles calculations for the temporal characteristics of hole-phonon relaxation in the valence band of titanium dioxide and zinc oxide have been performed. A first-principles method for the calculations of the quasistationary distribution function of holes has been developed. The results show that the quasistationary distribution of the holes in TiO2extends to an energy level approximately 1 eV below the top of the valence band. This conclusion in turn helps to elucidate the origin of the spectral dependence of the photocatalytic activity of TiO2. Analysis of the analogous data for ZnO shows that in this material spectral dependence of photocatalytic activity in the oxidative reactions is unlikely.

scholarly journals Combined first-principles calculations and experimental study on the photocatalytic mechanism of natural dolomite

RSC Advances ◽  
2021 ◽  
Vol 11 (39) ◽  
pp. 24416-24423
Author(s):  
Xiaomin Hou ◽  
Qi Cheng ◽  
Jianrong Wang ◽  
Qingfeng Wu ◽  
Weibin Zhang
Keyword(s):  
Experimental Study ◽  
Photocatalytic Activity ◽  
First Principles ◽  
Low Cost ◽  
Isomorphous Substitution ◽  
First Principles Calculations ◽  
Photocatalytic Mechanism

Natural dolomite exhibits notable photocatalytic activity due to the isomorphous substitution of Fe2+ for Mg2+ in the lattice, implying that it can be used as a low-cost photocatalyst.

Tailoring the photocatalytic activity of WO3 by Nb-F codoping from first-principles calculations

2018 ◽  
Vol 56 (5) ◽  
pp. 2285-2290
Author(s):  
Ying Xu ◽  
Ying Zhou ◽  
Guo Zheng Nie ◽  
Daifeng Zou ◽  
Zhi Min Ao
Keyword(s):  
Photocatalytic Activity ◽  
First Principles ◽  
First Principles Calculations

Size-dependent piezoelectricity in zinc oxide nanofilms from first-principles calculations

2007 ◽  
Vol 90 (3) ◽  
pp. 033108 ◽  
Author(s):  
Chun Li ◽  
Wanlin Guo ◽  
Yong Kong ◽  
Huajian Gao
Keyword(s):  
Zinc Oxide ◽  
First Principles ◽  
First Principles Calculations ◽  
Size Dependent

Interface States in SiO2/4H-SiC(0001) Interfaces from First-Principles: Effects of Si-Si Bonds and of Nitrogen Atom Termination

2005 ◽  
Vol 483-485 ◽  
pp. 573-576 ◽  
Author(s):  
Toshiharu Ohnuma ◽  
Hidekazu Tsuchida ◽  
Tamotsu Jikimoto ◽  
Atsumi Miyashita ◽  
Masahito Yoshikawa
Keyword(s):  
Nitrogen Atom ◽  
Valence Band ◽  
First Principles ◽  
Interface States ◽  
Band Edge ◽  
Valence Band Edge ◽  
First Principles Calculations ◽  
Dangling Bond

First-principles calculations for the abrupt SiO2/4H-SiC interfaces accounting for Si-Si bonding and Nitrogen atom termination have been performed. Interface states due to Si-Si bonds appear at the valence band edge. Interface states at the midgap vanish when N atom terminates the Si dangling bond, but the interface states arising from the Si-N bonds appear at the valence band edge at the same time.

Electronic structure and transport properties of ternary skutterudite: CoX3/2Y3/2

2009 ◽  
Vol 1166 ◽  
Author(s):  
Dmitri Volja ◽  
Marco Fornari ◽  
Boris Kozinsky ◽  
Nicola Marzari
Keyword(s):  
Electronic Structure ◽  
Transport Properties ◽  
Valence Band ◽  
Power Factor ◽  
First Principles ◽  
First Principles Calculations ◽  
Wannier Functions ◽  
Effective Masses ◽  
Fundamental Cause ◽  
Parabolic Dispersion

AbstractElectronic properties of ternary skutterudites AX3/2Y3/2 (A=Co, X=Ge, Sn and Y=S, Te) are investigated using first principles calculations to clarify recent experimental results. Band derivatives are computed accurately within an approach based on Maximally Localized Wannier Functions (MLWFs). Band structures exhibit larger effective masses compared to parental binary CoSb3. Our results also indicate a more parabolic dispersion near the top of the valence band and a multivalley character in both conduction and valence band. Despite the improved thermopower these skutterudites has relatively low power factor due to increased resistivity. The fundamental cause of such large resistivity seems to be associated with the ionicity of the bonding.

scholarly journals Transformation of the Topological Phase and the Edge Modes of Double-Bilayer Bismuthene with Inter-Bilayer Spacing

Crystals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 266 ◽  
Author(s):  
Huanzhi Hu ◽  
Zhibin Shi ◽  
Peng Wang ◽  
Weiping Zhou ◽  
Tai-Chang Chiang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Valence Band ◽  
Conduction Band ◽  
Topological Insulator ◽  
First Principles ◽  
Topological Phase ◽  
First Principles Calculations ◽  
Topological Phase Transition ◽  
Band Inversion ◽  
Band Insulator

The transformations of the topological phase and the edge modes of a double-bilayer bismuthene were investigated with first-principles calculations and Green’s function as the inter-bilayer spacing increased from 0 Å to 10 Å. At a critical spacing of 2 Å, a topological phase transition from a topological insulator to a band insulator resulting from a band inversion between the highest valence band and the second lowest conduction band, was observed, and this was understood based on the particular orbital characters of the band inversion involved states. The edge modes of double-bilayer bismuthene survived the phase transition. When d was 2 Å < d < 4 Å, the interaction between the edge modes of two separated bismuthene bilayers induced an anti-crossing gap and resulted in a trivial band connection. At and beyond 4 Å, the two bilayers behavior decoupled entirely. The results demonstrate the transformability of the topological phase and the edge modes with the inter-bilayer spacing in double-bilayer bismuthene, which may be useful for spintronic applications.

Understanding the adsorption behavior of surface active molecules on ZnO nanostructures by experimental and first-principles calculations

2015 ◽  
Vol 17 (45) ◽  
pp. 30450-30460 ◽  
Author(s):  
Baljinder Singh ◽  
Satvinder Singh ◽  
Janpreet Singh ◽  
G. S. S. Saini ◽  
D. S. Mehta ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Sodium Dodecyl Sulphate ◽  
First Principles ◽  
Chemical Method ◽  
Sodium Dodecyl ◽  
Tween 80 ◽  
Zno Nanostructures ◽  
First Principles Calculations ◽  
Surface Active ◽  
Triton X

Zinc oxide (ZnO) nanostructures with different morphologies are prepared in the presence of surface active molecules such as sodium dodecyl sulphate (SDS), Tween 80 and Triton X-100 by a chemical method.

Interaction of Pyrene Ligands with Neat and Defective Two Dimensional ZnO: A First Principles Study

MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2799-2805
Author(s):  
Velappa Jayaraman Surya ◽  
Yuvaraj Sivalingam ◽  
Velappa Jayaraman Sowmya ◽  
Palani Elumalai ◽  
Gabriele Magna ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Band Gap ◽  
Research Group ◽  
First Principles ◽  
2D Materials ◽  
Zno Nanorods ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Comb Structure ◽  
Finite Band

ABSTRACTMany heterogeneous and flat two dimensional (2D) materials with finite band gap have been researched for its suitability in exotic applications. For instance, zinc oxide (ZnO) with honey comb structure has optimum band gap that makes it eligible for opto-electronic applications. Recently, our research group have found that pyrene based tetratopic ligands (PTL) are suitable for functionalizing ZnO nanorods. In this study, neat and defective 2D ZnO layer is functionalized with different pyrene based ligands with various functional groups. First principles calculations are done and the degree of affinity of pyrene ligands towards neat and defective ZnO sheets is compared.

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