scholarly journals Theoretical Investigation on the Complexation Characteristics and Spectral Properties of CdTe QDs With Four Capping Agents

2021 ◽  
Author(s):  
Qinghong Yang ◽  
Xujiang Wan ◽  
Yang Chen ◽  
Hui Luo ◽  
Yan Zheng ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Visible Light ◽  
Density Functional ◽  
Reduced Glutathione ◽  
Functional Theory ◽  
Capping Agents ◽  
Absorption Intensity ◽  
Cdte Qds ◽  
Uv Visible ◽  
The Stability

Abstract In this paper, density functional theory (DFT) and time-dependent density functional theory (TDDFT) are used to study the complexation characteristics CdTe quantum dots with four different capping agents, i.e. : 3-mercaptopropionic acid (MPA), reduced glutathione (GSH), 1-thioglycerol (TG) and 2-mercaptoethanesulfonate (MES). The properties of these complexes are analyzed by the complexation energy, bond lengths, electron densities, Mulliken charges and frontier molecular orbitals. In addition, the UV-Vis absorption spectra of pure CdTe QDs and those stable complexes are calculated. The results indicate that the four capping agents could form stable complexes with CdTe QDs. However, there are also some differences. For instance, the complexation between MES and QDs is the most stable and the electron amount transferred from MES to CdTe QDs is the most while the absorption intensity of UV-visible light after complexation is the largest. The stability of the complexes are followed by MPA and TG and the complexation between GSH and QDs is the most unstable, which is accompanied with the minimal electron transfer amount and the weakest absorption intensity of UV-visible light. The maximum absorption wavelengths of CdTe QDs are consistent with the experimental observed wavelength, which explains the experimental phenomena excellently.

scholarly journals The stability and electronic and photocatalytic properties of the ZnWO4 (010) surface determined from first-principles and thermodynamic calculations

RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23477-23490
Author(s):  
Yonggang Wu ◽  
Jihua Zhang ◽  
Bingwei Long ◽  
Hong Zhang
Keyword(s):  
Phase Diagram ◽  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Thermodynamic Calculations ◽  
Photocatalytic Properties ◽  
Thermodynamic Approach ◽  
Functional Theory ◽  
Stability Phase Diagram ◽  
The Stability

The ZnWO4 (010) surface termination stability is studied using a density functional theory-based thermodynamic approach. The stability phase diagram shows that O-Zn, DL-W, and DL-Zn terminations of ZnWO4 (010) can be stabilized.

Electronic Structure and Optical Properties of Non-Metals (N, F, P, Cl, S)-Doped Cubic NaTaO3 by Density Functional Theory

2009 ◽  
Vol 79-82 ◽  
pp. 1245-1248 ◽  
Author(s):  
Pei Lin Han ◽  
Xiao Jing Wang ◽  
Yan Hong Zhao ◽  
Chang He Tang
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Electronic Structure ◽  
Visible Light ◽  
Absorption Edge ◽  
Density Functional ◽  
Red Shift ◽  
Functional Theory ◽  
Photoactive Materials ◽  
Metal Doped

Electronic structure and optical properties of non-metals (N, S, F, P, Cl) -doped cubic NaTaO3 were investigated systematically by density functional theory (DFT). The results showed that the substitution of (N, S, P, Cl) for O in NaTaO3 was effective in narrowing the band-gap relative to the F-doped NaTaO3. The larger red shift of the absorption edge and the higher visible light absorption at about 520 nm were found for the (N and P)-doped NaTaO3. The excitation from the impurity states to the conduction band may account for the red shift of the absorption edge in an electron-deficiency non-metal doped NaTaO3. The obvious absorption in the visible light region for (N and P)-doped NaTaO3 provides an important guidance for the design and preparation of the visible light photoactive materials.

Predicting the stability of ternary intermetallics with density functional theory and machine learning

2018 ◽  
Vol 148 (24) ◽  
pp. 241728 ◽  
Author(s):  
Jonathan Schmidt ◽  
Liming Chen ◽  
Silvana Botti ◽  
Miguel A. L. Marques
Keyword(s):  
Machine Learning ◽  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
The Stability

Targeting complex plutonium oxides by combining crystal chemical reasoning with density-functional theory calculations: the quaternary plutonium oxide Cs2PuSi6O15

2020 ◽  
Vol 56 (66) ◽  
pp. 9501-9504
Author(s):  
Kristen A. Pace ◽  
Vladislav V. Klepov ◽  
Matthew S. Christian ◽  
Gregory Morrison ◽  
Travis K. Deason ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Crystal Growth ◽  
Dft Calculations ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Crystal Chemical ◽  
The Novel ◽  
Functional Theory ◽  
The Stability ◽  
Chemical Reasoning

The stability of the novel Pu(iv) silicate, Cs2PuSi6O15, was predicted from a combination of crystal chemical reasoning and DFT calculations and confirmed by its synthesis via flux crystal growth.

scholarly journals Experimental and DFT Studies of Au Deposition Over WO3/g-C3N4 Z-Scheme Heterojunction

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Muhammad Humayun ◽  
Habib Ullah ◽  
Junhao Cao ◽  
Wenbo Pi ◽  
Yang Yuan ◽  
...  
Keyword(s):  
Visible Light ◽  
Density Functional ◽  
Resonance Effect ◽  
State Density ◽  
Functional Theory ◽  
Co Catalysts ◽  
Redox Couples ◽  
Bonding Interaction ◽  
Wet Chemical ◽  
The Stability

AbstractA typical Z-scheme system is composed of two photocatalysts which generate two sets of charge carriers and split water into H2 and O2 at different locations. Scientists are struggling to enhance the efficiencies of these systems by maximizing their light absorption, engineering more stable redox couples, and discovering new O2 and H2 evolutions co-catalysts. In this work, Au decorated WO3/g-C3N4 Z-scheme nanocomposites are fabricated via wet-chemical and photo-deposition methods. The nanocomposites are utilized in photocatalysis for H2 production and 2,4-dichlorophenol (2,4-DCP) degradation. It is investigated that the optimized 4Au/6% WO3/CN nanocomposite is highly efficient for production of 69.9 and 307.3 µmol h−1 g−1 H2 gas, respectively, under visible-light (λ > 420 nm) and UV–visible illumination. Further, the fabricated 4Au/6% WO3/CN nanocomposite is significant (i.e., 100% degradation in 2 h) for 2,4-DCP degradation under visible light and highly stable in photocatalysis. A significant 4.17% quantum efficiency is recorded for H2 production at wavelength 420 nm. This enhanced performance is attributed to the improved charge separation and the surface plasmon resonance effect of Au nanoparticles. Solid-state density functional theory simulations are performed to countercheck and validate our experimental data. Positive surface formation energy, high charge transfer, and strong non-bonding interaction via electrostatic forces confirm the stability of 4Au/6% WO3/CN interface.

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