Oxygen vacancy induced electron traps in tungsten doped Bi2MoO6 for enhanced photocatalytic performance

CrystEngComm ◽  
2021 ◽  
Author(s):  
Chang Sun ◽  
Zitong Zhao ◽  
Hougang Fan ◽  
Yanli Chen ◽  
Xiaoyan Liu ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Recombination Rate ◽  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
Electron Trap ◽  
Electron Traps

As the concentration of the W dopant increased in the Bi2Mo1−xWxO6 nanosheets, the density of the oxygen vacancies became higher, which served as electron trap centers to lower the recombination rate and enhance the photocatalytic performance.

Determining the Role of Oxygen Vacancies in the Photocatalytic Performance of WO3 for Water Oxidation

2019 ◽  
Author(s):  
Sacha Corby ◽  
Laia Francàs ◽  
Andreas Kafizas ◽  
James R Durrant
Keyword(s):  
Oxygen Vacancy ◽  
Charge Carrier ◽  
Water Oxidation ◽  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
Photoelectrochemical Performance ◽  
Solar Water Splitting ◽  
The Impact ◽  
Recombination Kinetics ◽  
Vacancy Concentrations

Oxygen vacancies are common to most metal oxides, whether intentionally incorporated or otherwise, and the study of these defects is of increasing interest for solar water splitting. In this work, we examine nanostructured WO<sub>3</sub> photoanodes of varying oxygen content to determine how the concentration of bulk oxygen-vacancy states affects the photocatalytic performance for water oxidation. Using transient optical spectroscopy, we follow the charge carrier recombination kinetics in these samples, from picoseconds to seconds, and examine how differing oxygen vacancy concentrations impact upon these kinetics. We find that samples with an intermediate concentration of vacancies (~2% of oxygen atoms) afford the greatest photoinduced charge carrier densities, and the slowest recombination kinetics across all timescales studied. This increased yield of photogenerated charges correlates with improved photocurrent densities under simulated sunlight, with both greater and lesser oxygen vacancy concentrations resulting in enhanced recombination losses and poorer J-V performances. Our conclusion, that an optimal – neither too high nor too low – concentration of oxygen vacancies is required for optimum photoelectrochemical performance, is discussed in terms of the impact of these defects on charge separation and transport, as well as the implications held for other highly doped materials for photoelectrochemical water oxidation.

Determining the Role of Oxygen Vacancies in the Photocatalytic Performance of WO3 for Water Oxidation

2019 ◽  
Author(s):  
Sacha Corby ◽  
Laia Francàs ◽  
Andreas Kafizas ◽  
James R Durrant
Keyword(s):  
Oxygen Vacancy ◽  
Charge Carrier ◽  
Water Oxidation ◽  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
Photoelectrochemical Performance ◽  
Solar Water Splitting ◽  
The Impact ◽  
Recombination Kinetics ◽  
Vacancy Concentrations

Oxygen vacancies are common to most metal oxides, whether intentionally incorporated or otherwise, and the study of these defects is of increasing interest for solar water splitting. In this work, we examine nanostructured WO<sub>3</sub> photoanodes of varying oxygen content to determine how the concentration of bulk oxygen-vacancy states affects the photocatalytic performance for water oxidation. Using transient optical spectroscopy, we follow the charge carrier recombination kinetics in these samples, from picoseconds to seconds, and examine how differing oxygen vacancy concentrations impact upon these kinetics. We find that samples with an intermediate concentration of vacancies (~2% of oxygen atoms) afford the greatest photoinduced charge carrier densities, and the slowest recombination kinetics across all timescales studied. This increased yield of photogenerated charges correlates with improved photocurrent densities under simulated sunlight, with both greater and lesser oxygen vacancy concentrations resulting in enhanced recombination losses and poorer J-V performances. Our conclusion, that an optimal – neither too high nor too low – concentration of oxygen vacancies is required for optimum photoelectrochemical performance, is discussed in terms of the impact of these defects on charge separation and transport, as well as the implications held for other highly doped materials for photoelectrochemical water oxidation.

Oxygen vacancy engineered SrTiO3 nanofibers for enhanced photocatalytic H2 production

2019 ◽  
Vol 7 (30) ◽  
pp. 17974-17980 ◽  
Author(s):  
Chuan-Qi Li ◽  
Sha-Sha Yi ◽  
De-liang Chen ◽  
Yan Liu ◽  
Ya-Jie Li ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Active Sites ◽  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
H2 Production

Cocatalysts-free SrTiO3 nanofibers with high photocatalytic performance are developed by incorporating oxygen vacancies (OVs), where OVs could steer charge behaviors, serve as active sites and heighten reduction ability of electrons.

scholarly journals Моделирование атомной и электронной структуры вакансий и поливакансий кислорода в ZrO-=SUB=-2-=/SUB=-

2018 ◽  
Vol 60 (3) ◽  
pp. 421
Author(s):  
T.B. Перевалов
Keyword(s):  
Electronic Structure ◽  
Oxygen Vacancy ◽  
Zirconium Oxide ◽  
Quantum Chemical ◽  
Oxygen Vacancies ◽  
Electron Trap ◽  
Chemical Modeling ◽  
Preferential Localization ◽  
O Vacancy ◽  
Atomic And Electronic Structure

AbstractCubic, tetragonal, and monoclinic phases of zirconium oxide with oxygen vacancies and polyvacancies are studied by quantum chemical modeling of the atomic and electronic structure. It is demonstrated that an oxygen vacancy in ZrO_2 may act as both an electron trap and a hole one. An electron added to the ZrO_2 structure with an oxygen vacancy is distributed between two neighboring Zr atoms and is a bonding orbital by nature. It is advantageous for each subsequent O vacancy to form close to the already existing ones; notably, one Zr atom has no more than two removed O atoms related to it. Defect levels from oxygen polyvacancies are distributed in the bandgap with preferential localization in the vicinity of the oxygen monovacancy level.

Chemoselective Hydrogenation of Cinnamaldehyde over Tailored Oxygen Vacancy Rich Pd@ZrO2 Catalyst

2021 ◽  
Author(s):  
Komal N. Patil ◽  
Divya Prasad ◽  
Jayesh T. Bhanushali ◽  
Bhalchandra Kakade ◽  
Arvind H. Jadhav ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Selective Hydrogenation ◽  
Oxygen Vacancies ◽  
Synthesis Method ◽  
Chemoselective Hydrogenation ◽  
Zro2 Catalyst ◽  
Industrial Relevance

Selective hydrogenation of cinnamaldehyde to hydrocinnamaldehyde is captivating due to its industrial relevance. Herein, two-step synthesis method was adopted to develop oxygen vacancies in Pd@ZrO2 catalysts. The oxygen vacancies were...

In situ synthesis of Cl-doped Bi2O2CO3 and its enhancement of photocatalytic activity by inducing generation of oxygen vacancies

2020 ◽  
Vol 7 (16) ◽  
pp. 2969-2978
Author(s):  
Jie-hao Li ◽  
Jie Ren ◽  
Ying Liu ◽  
Hui-ying Mu ◽  
Rui-hong Liu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Ionic Liquids ◽  
Oxygen Vacancy ◽  
Oxygen Vacancies ◽  
In Situ Synthesis ◽  
Photocatalytic Mechanism

Cl-Doped Bi2O2CO3 is prepared using ionic liquids as dopants and the oxygen-vacancy-induced photocatalytic mechanism is revealed.

A hierarchical oxygen vacancy-rich WO3 with “nanowire-array-on-nanosheet-array” structure for highly efficient oxygen evolution reaction

2019 ◽  
Vol 7 (12) ◽  
pp. 6730-6739 ◽  
Author(s):  
Jinxiang Diao ◽  
Wenyu Yuan ◽  
Yu Qiu ◽  
Laifei Cheng ◽  
Xiaohui Guo
Keyword(s):  
Oxygen Vacancy ◽  
Oxygen Evolution Reaction ◽  
Oxygen Vacancies ◽  
State Of The Art ◽  
Nanowire Array ◽  
Nanowire Arrays ◽  
Nanosheet Array ◽  
Nanosheet Arrays ◽  
Array Structure ◽  
First Time

Hierarchical vertical WO3 nanowire arrays on vertical WO3 nanosheet arrays with rich oxygen vacancies were synthesized via a simple and facile method, and the outstanding OER performance which is superior to that of most reported state-of-the-art catalysts was reported for the first time.

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