Adsorption of Water Molecules on Flat and Stepped Nickel Surfaces from First Principles

2004 ◽  
Vol 1 (1) ◽  
pp. 78-82 ◽  
Author(s):  
Daniel Sebastiani ◽  
Luigi Delle Site
Keyword(s):  
First Principles ◽  
Water Molecules ◽  
Adsorption Of Water

Adsorption of water molecules on the surface of photo-catalyst: a first principles theoretical comparison between InVO4 and rutile TiO2

2002 ◽  
Vol 751 ◽  
Author(s):  
M. Oshikiri ◽  
M. Boero ◽  
J. Ye
Keyword(s):  
First Principles ◽  
Water Adsorption ◽  
Adsorption Process ◽  
Catalyst Surface ◽  
Chemical Reactivity ◽  
Water Molecules ◽  
Activation Energy Barrier ◽  
Reaction Proceeds ◽  
Adsorption Of Water ◽  
Dynamics Simulations

ABSTRACTThe adsorption process of water molecules on the surface of InVO4 has been investigated via first principles molecular dynamics simulations and compared with that of the well-known rutile TiO2. We have found that the surface of InVO4 shows a remarked chemical reactivity whenever comes in contact with water and H2O molecules are often adsorbed dissociatively on its surface. The reaction proceeds spontaneously in a way similar to the case of TiO2 and does not require the overcoming of an activation energy barrier. The peculiar atomic connectivity of the InVO4 bulk crystal structure and the changes at the catalyst surface induced by the water adsorption are discussed and compared with the TiO2 system.

Adosorption of H2O on the Inside Surface of B-N Co-Doped Carbon Nanotube

2011 ◽  
Vol 480-481 ◽  
pp. 132-136 ◽  
Author(s):  
Jian Wei Wei ◽  
Hui Zeng ◽  
Li Chun Pu ◽  
Nan Hu
Keyword(s):  
Carbon Nanotube ◽  
First Principles ◽  
Electronic Structures ◽  
Local Density ◽  
Inside Surface ◽  
Water Molecules ◽  
Local Density Of States ◽  
Adsorption Of Water ◽  
Co Doped ◽  
Slight Deformation

In this paper, we have investigated the geometries and electronic structures of B-N co-doped carbon nanotube with inside adsorption of water molecules. The charge distributions, band structures and local density of states are calculated by using the first-principles theory in detail. The results show that the water molecules can adsorb stably on the inside surface of the doped nanotube with slight deformation. The π and π* subbands shift upward depending on the sites of the adoptions. The investigations will be beneficial to the biological application of B-N co-doped nanotube.

First-Principles Study of H2O Adsorption on Oxygen-Covered Fe Surface

2012 ◽  
Vol 706-709 ◽  
pp. 1481-1484 ◽  
Author(s):  
Norio Nunomura ◽  
Satoshi Sunada
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Water Molecules ◽  
First Principle ◽  
Surface Oxygen ◽  
Functional Theory ◽  
First Principle Calculations ◽  
Oxygen Coverage ◽  
Adsorption Of Water

We present the results from first principle calculations of H2O adsorption on oxygen-covered Fe (100) surface. The calculations are based on a density-functional theory, surface modeling which uses supercell slab models. As a surface oxygen coverage increases, the surface is not activated, which makes the adsorption of water molecules on Fe surface unfavorable. It has been found that the surface covered oxygen exerts an influence on the adsorption of H2O molecule on Fe surface.

A First-Principles Computational Comparison of the Aqueous Anatase TiO2 (001) Interface and the Disordered, Fluorinated TiO2 Interface

2018 ◽  
Author(s):  
Kyle Reeves ◽  
Damien Dambournet ◽  
Christel Laberty-Robert ◽  
Rodolphe Vuilleumier ◽  
Mathieu Salanne
Keyword(s):  
Density Of States ◽  
Density Functional ◽  
Water Dissociation ◽  
Water Molecules ◽  
Chemical Doping ◽  
Charge Balance ◽  
Functional Theory ◽  
Adsorption Of Water ◽  
Properties Of Materials ◽  
Computational Comparison

Chemical doping and other surface modifications have been used to engineer the bulk properties of materials, but their influence on the surface structure and consequently the surface chemistry are often unknown. Previous work has been successful in fluorinating anatase TiO<sub>2</sub> with charge balance achieved via the introduction of Ti vacancies rather than the reduction of Ti. Our work here investigates the interface between this fluorinated titanate with cationic vacancies and a<br>monolayer of water via density functional theory based molecular dynamics. We compute the projected density of states for only those atoms at the interface and for those states that fall within 1eV of the Fermi energy for various steps throughout the simulation, and we determine that the<br>variation in this representation of the density of states serves as a reasonable tool to anticipate where surfaces are most likely to be reactive. In particular, we conclude that water dissociation at the surface is the main mechanism that influences the anatase (001) surface whereas the change in<br>the density of states at the surface of the fluorinated structure is influenced primarily through the adsorption of water molecules at the surface.

A First-Principles Computational Comparison of the Aqueous Anatase TiO2 (001) Interface and the Disordered, Fluorinated TiO2 Interface

2018 ◽  
Author(s):  
Kyle Reeves ◽  
Damien Dambournet ◽  
Christel Laberty-Robert ◽  
Rodolphe Vuilleumier ◽  
Mathieu Salanne
Keyword(s):  
Density Of States ◽  
Density Functional ◽  
Water Dissociation ◽  
Water Molecules ◽  
Chemical Doping ◽  
Charge Balance ◽  
Functional Theory ◽  
Adsorption Of Water ◽  
Properties Of Materials ◽  
Computational Comparison

Chemical doping and other surface modifications have been used to engineer the bulk properties of materials, but their influence on the surface structure and consequently the surface chemistry are often unknown. Previous work has been successful in fluorinating anatase TiO<sub>2</sub> with charge balance achieved via the introduction of Ti vacancies rather than the reduction of Ti. Our work here investigates the interface between this fluorinated titanate with cationic vacancies and a<br>monolayer of water via density functional theory based molecular dynamics. We compute the projected density of states for only those atoms at the interface and for those states that fall within 1eV of the Fermi energy for various steps throughout the simulation, and we determine that the<br>variation in this representation of the density of states serves as a reasonable tool to anticipate where surfaces are most likely to be reactive. In particular, we conclude that water dissociation at the surface is the main mechanism that influences the anatase (001) surface whereas the change in<br>the density of states at the surface of the fluorinated structure is influenced primarily through the adsorption of water molecules at the surface.

scholarly journals Electrical Breakdown Mechanism of Transformer Oil with Water Impurity: Molecular Dynamics Simulations and First-Principles Calculations

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 123
Author(s):  
Bin Cao ◽  
Ji-Wei Dong ◽  
Ming-He Chi
Keyword(s):  
Molecular Dynamics ◽  
Thermal Diffusion ◽  
First Principles ◽  
Electrical Breakdown ◽  
Transformer Oil ◽  
Water Molecules ◽  
Conducting Channel ◽  
Breakdown Mechanism ◽  
Water Impurity ◽  
Dynamics Simulations

Water impurity is the essential factor of reducing the insulation performance of transformer oil, which directly determines the operating safety and life of a transformer. Molecular dynamics simulations and first-principles electronic-structure calculations are employed to study the diffusion behavior of water molecules and the electrical breakdown mechanism of transformer oil containing water impurities. The molecular dynamics of an oil-water micro-system model demonstrates that the increase of aging acid concentration will exponentially expedite thermal diffusion of water molecules. Density of states (DOS) for a local region model of transformer oil containing water molecules indicates that water molecules can introduce unoccupied localized electron-states with energy levels close to the conduction band minimum of transformer oil, which makes water molecules capable of capturing electrons and transforming them into water ions during thermal diffusion. Subsequently, under a high electric field, water ions collide and impact on oil molecules to break the molecular chain of transformer oil, engendering carbonized components that introduce a conduction electronic-band in the band-gap of oil molecules as a manifestation of forming a conductive region in transformer oil. The conduction channel composed of carbonized components will be eventually formed, connecting two electrodes, with the carbonized components developing rapidly under the impact of water ions, based on which a large number of electron carriers will be produced similar to “avalanche” discharge, leading to an electrical breakdown of transformer oil insulation. The water impurity in oil, as the key factor for forming the carbonized conducting channel, initiates the electric breakdown process of transformer oil, which is dominated by thermal diffusion of water molecules. The increase of aging acid concentration will significantly promote the thermal diffusion of water impurities and the formation of an initial conducting channel, accounting for the degradation in dielectric strength of insulating oil containing water impurities after long-term operation of the transformer.

A first-principles study of the atomic layer deposition of ZnO on carboxyl functionalized carbon nanotubes: the role of water molecules

2021 ◽  
Vol 23 (5) ◽  
pp. 3467-3478
Author(s):  
J. I. Paez-Ornelas ◽  
H. N. Fernández-Escamilla ◽  
H. A. Borbón-Nuñez ◽  
H. Tiznado ◽  
Noboru Takeuchi ◽  
...  
Keyword(s):  
First Principles ◽  
Ligand Exchange ◽  
Functional Group ◽  
Atomic Layer ◽  
High Reactivity ◽  
Water Molecules ◽  
Exchange Reactions ◽  
Layer Deposition ◽  
The Right

Atomic description of ALD in systems that combine large surface area and high reactivity is key for selecting the right functional group to enhance the ligand-exchange reactions.

Sign in / Sign up

Export Citation Format

Share Document