Theoretical study of surface dependence of NH3 adsorption and decomposition on spinel-type MgAl2O4

RSC Advances ◽  
2015 ◽  
Vol 5 (95) ◽  
pp. 77973-77985 ◽  
Author(s):  
Huan Wang ◽  
Chuanyi Jia ◽  
Jing Yang ◽  
Xian Zhao ◽  
Yanlu Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Surface Reconstruction ◽  
Density Functional ◽  
Theoretical Study ◽  
Spinel Type ◽  
Functional Theory ◽  
Oxygen Defects ◽  
Nh3 Adsorption ◽  
Adsorption And Dissociation

The effects of the surface reconstruction and oxygen defects on the NH3 adsorption and dissociation on MgAl2O4 (100), (110), and (111) surfaces were studied based on density functional theory (DFT) slab calculations.

A theoretical study on solvatofluorochromic asymmetric thiazolothiazole (TTz) dyes using dielectric-dependent density functional theory

2021 ◽  
Vol 23 (37) ◽  
pp. 21078-21086
Author(s):  
Tomomi Shimazaki ◽  
Masanori Tachikawa
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Study ◽  
Dye Molecules ◽  
Excitation Energies ◽  
Functional Theory ◽  
Dependent Density

In this work, the excitation energies of asymmetric thiazolothizaole (TTz) dye molecules have been theoretically studied using dielectric-dependent density functional theory (DFT).

Computational investigation of NH3 adsorption and dehydrogenation on a W-modified Fe(111) surface

2015 ◽  
Vol 17 (45) ◽  
pp. 30598-30605 ◽  
Author(s):  
Ming-Kai Hsiao ◽  
Chia-Hao Su ◽  
Ching-Yang Liu ◽  
Hui-Lung Chen
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Computational Investigation ◽  
Functional Theory ◽  
Nh3 Adsorption ◽  
Tungsten Metal

We employed monolayer tungsten metal to modify the Fe(111) surface, denoted as W@Fe(111), and calculated the adsorption and dehydrogenation behaviors of NH3 on W@Fe(111) surface via first-principles calculations based on density functional theory (DFT).

DENSITY FUNCTIONAL THEORY STUDY OF H2O ADSORPTION AND DISSOCIATION ON Al (111) SURFACE

2013 ◽  
Vol 12 (05) ◽  
pp. 1350035 ◽  
Author(s):  
LIXIA YANG ◽  
XIAOLI LEI ◽  
JUN FENG ◽  
YUXIN ZHANG ◽  
MINGXING LIU
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Catalytic Effect ◽  
Geometry Optimization ◽  
Vacancy Defect ◽  
Hydroxyl Group ◽  
Dissociation Pathway ◽  
Functional Theory ◽  
Lower Activation ◽  
Adsorption And Dissociation

Comparative study about the adsorption and dissociation behaviors of H2O molecule on clean and vacancy defective Al (111) surface was conducted by extensive density functional theory (DFT) calculations, the interaction mechanisms between H2O molecule and Al (111) surface were also figured out. Geometry optimization results indicated that H2O molecule was apt to be adsorbed at top site on these two kinds of surfaces, whereas, the adsorption configurations, the adsorption type and inclination of H2O molecule planes away from the normal were different. The calculated adsorption energies demonstrated that the adsorption of H2O molecule occurred more readily on vacancy defective Al (111) surface. The electron density distribution indicated that the vacancy defect enhanced the interactions between H2O molecule and surface Al atoms. Further analysis of the density of states (DOS) showed that the vacancy defect increased the number of bonding electrons between H2O molecule and surface Al atoms. The detailed exploration of dissociation pathways demonstrated that the dissociation of H2O molecule on these two kinds of surfaces was a two-step process: (1) H2O → H + OH , (2) OH → H + O . However, for each step the dissociation pathway variations on vacancy defective Al (111) surface were different with those on clean Al (111) surface. Compared with the first step, the dissociation of hydroxyl group into O atom and H atom was kinetically difficult. The calculated lower activation energy barriers on vacancy defective Al (111) surface showed that the vacancy defect had catalytic effect for the dissociation of H2O molecule to some extent, especially for the first step.

Insights from Density Functional Theory Calculations into the Effects of the Adsorption and Dissociation of Water on the Surface Properties of Zinc Diphosphide (ZnP2) Nanocrystals

2021 ◽  
Author(s):  
Barbara Farkas ◽  
Aleksandar Zivkovic ◽  
Veikko Uahengo ◽  
Nelson Yaw Dzade ◽  
Nora Henriette De Leeuw
Keyword(s):  
Density Functional Theory ◽  
Surface Structure ◽  
Surface Properties ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Photovoltaic Applications ◽  
Zinc Diphosphide ◽  
Adsorption And Dissociation

Zinc phosphides (ZnP2 and Zn3P2) are emerging absorber materials for photovoltaic applications owing to their abundancy and non-toxic nature. Herein, we provide a comprehensive characterisation of the surface structure, composition,...

A Theoretical Study of H2S Toxic Gas Adsorption on Pristine and Doped Monolayer (AlN)21 Using Density Functional Theory

2020 ◽  
Vol 12 (02) ◽  
pp. 99-111
Author(s):  
Jamal A. Shlaka ◽  
◽  
Abbas H. Abo Nasria
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Study ◽  
Gas Adsorption ◽  
Aluminium Nitride ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Gas Molecules ◽  
Toxic Gas ◽  
Center Ring

Been studying the interactions between graphene - like aluminium nitride P(AlN)21 nano ribbons doped and defect (AlN)21Sheet, Molecules and small toxic gas molecules ( H2S), were built for two different adsorption sites on graphene like aluminium nitride P(AlN)21. this was done by employing B3LYP density functional theory (DFT) with 6-31G*(d,p) using Gaussian 09 program, Gaussian viw5.0 package of programs and Nanotube Modeller program 2018. the adsorptions of H2S on P(AlN)21, (C) atoms-doped P(AL-N)20 sheet, D-P(AL-N)20 and D-(C)atoms-doped P(AL-N)19 (on atom) with (Ead) (-0.468eV),(-0.473 eV), (-0.457 eV), (-0.4478 eV) and (-0.454 eV), respectively, (Ead) of H2S on the center ring of the P(AL-N)21, (C) atoms-doped P(AL-N)20 sheet, D-P(AL-N)20 and D-(C,B)atoms-doped P(AL-N)19 sheet are (-0.280 eV),(-0.465 eV), (-0.405 eV), (-0.468 eV) and -0.282 eV), respectively, are weak physisorption . However, the adsorptions of H2S, on the ((AlN)20 -B and D- (AlN)19 -B), (on atom N and center ring the sheet) are a strong chemisorption because of the (Ead) larger than -0.5 eV, due to the strong interaction, the ((AlN)20-B and D-(AlN)19-B), could catalyst or activate, through the results that we obtained, which are the improvement of the sheet P(AlN)21 by doping and per forming a defect in, it that can be used to design sensors. DOI: http://dx.doi.org/10.31257/2018/JKP/2020/120210

Meso-alkynyl corroles and their cobalt(III), manganese(III) and gallium(III) complexes

2020 ◽  
Vol 24 (05n07) ◽  
pp. 737-749
Author(s):  
Michael Haas ◽  
Sabrina Gonglach ◽  
Wolfgang Schöfberger
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Theoretical Study ◽  
Lumo Energy ◽  
Functional Theory ◽  
Energy Gaps ◽  
Peak Broadening ◽  
Homo And Lumo ◽  
Homo Lumo

We report routes towards synthesis of novel [Formula: see text]-conjugated freebase cobalt, copper, gallium and manganese meso-alkynylcorroles. UV-vis spectra show that extensive peak broadening, red shifts, and changes in the oscillator strength of absorptions increase with the extension of [Formula: see text]-conjugation. Using density functional theory (DFT), we have carried out a first theoretical study of the electronic structure of these metallocorroles. Decreased energy gaps of about 0.3–0.4 eV between the HOMO and LUMO orbitals compared to the corresponding copper, gallium and manganese meso-5,10,15 triphenylcorrole are observed. In all cases, the HOMO energies are nearly unperturbed as the [Formula: see text]-conjugation is expanded. The contraction of the HOMO–LUMO energy gaps is attributed to the lowered LUMO energies.

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