The surface hydroxyl and oxygen vacancy dependent Cr(vi) adsorption performance of BiOCl

2020 ◽  
Vol 7 (5) ◽  
pp. 1454-1463 ◽  
Author(s):  
Guangming Zhan ◽  
Jie Li ◽  
Yue Hu ◽  
Shengxi Zhao ◽  
Shiyu Cao ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Oxygen Vacancies ◽  
Surface Defects ◽  
Adsorption Behavior ◽  
Mineral Surfaces ◽  
Coordination Environment ◽  
Surface Hydroxyl ◽  
Adsorption Performance ◽  
Natural Surface ◽  
Surface Hydroxyls

The migration and bioavailability of Cr(vi) are determined by its adsorption behavior, which is sensitive to the coordination environment of mineral surfaces, especially natural surface defects, such as surface hydroxyls and oxygen vacancies.

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.

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.

Oxygen vacancy migration in CSZ using density functional theory

2008 ◽  
Vol 1122 ◽  
Author(s):  
Byeong-Eon Lee ◽  
Dae-Hee Kim ◽  
Yeong-Cheol Kim
Keyword(s):  
Density Functional Theory ◽  
Oxygen Vacancy ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Nearest Neighbor ◽  
Functional Theory ◽  
The Third ◽  
Vacancy Migration ◽  
Neighbor Site ◽  
Formation Energies

AbstractWe studied oxygen migration in calcia-stabilized cubic zirconia (CSZ) using density functional theory. A Ca atom was substituted for a Zr atom in a 2×2×2 ZrO2 cubic supercell, and an oxygen vacancy was produced to satisfy the charge neutrality condition. We found that the formation energies of an oxygen vacancy, as a function of its location with respect to the Ca atom, were varied. The relative formation energies of the oxygen vacancies located at the first-, second-, third-, and fourth-nearest-neighbors were 0.0, −0.07, 0.19, and 0.19 eV, respectively. Therefore, the oxygen vacancy located at the second-nearest-neighbor site of the Ca atom was the most favorable, the oxygen vacancy located at the first-nearest-neighbor site was the second most favorable, and the oxygen vacancies at the third- and fourth-nearest-neighbor sites were the least favorable. We also calculated the energy barriers for the oxygen vacancy migration between oxygen sites. The energy barriers between the first and the second nearest sites, the second and third nearest sites, and the third and fourth nearest sites were 0.11, 0.46, and 0.23 eV, respectively. Therefore, the oxygen vacancies favored the first- and second-nearest-neighbor oxygen sites when they drifted under an electric field.

The Effect of Oxygen Vacancies on the Dielectric Responses of BaTiO3 Based Ceramics in the Ultra-Wide Frequency Range

2011 ◽  
Vol 485 ◽  
pp. 15-18 ◽  
Author(s):  
Youn Kyu Choi ◽  
Takuya Hoshina ◽  
Hiroaki Takeda ◽  
Jong Min Oh ◽  
Takaaki Tsurumi
Keyword(s):  
Oxygen Vacancy ◽  
Oxygen Vacancies ◽  
Wide Frequency Range ◽  
Annealing Conditions ◽  
Mass Fractions ◽  
Xrd Patterns ◽  
Effect Of Oxygen ◽  
Lattice Hardening ◽  
Dipole Polarization ◽  
Ionic Polarization

The effect of oxygen vacancies and their migrations on the dielectric responses of BaTiO3 (BT) ceramics and (Ba, Ca)(Ti, Zr)O3 (BCTZ) ceramics was studied using wideband dielectric spectroscopy. Both dipole and ionic polarization of BT ceramics after annealing in a reducing atmosphere markedly decreased. To elucidate the decrease of dipole and ionic polarization, we observed the domain width and the crystal structure of BT ceramics annealed in different PO2. The mass fractions of constituted phases in 90o domain were calculated using the refinement of XRD patterns to explain the degradation of ionic polarization by oxygen vacancies. From the results above, we judged that the decrease of dipole polarization was due to the domain wall clamping by oxygen vacancies, while that of ionic polarization was attributable to the lattice hardening by the incorporation of oxygen vacancies into the BT lattice. In the case of BCTZ ceramics, dipole polarization showed the same way as BT ceramics with annealing conditions but the ionic polarization was independent of PO2 in annealing because of anti-reducing behavior of BCTZ ceramics. On the basis of the effect of oxygen vacancy in BT ceramics and BCTZ ceramics, we could clarify the oxygen vacancy migration in BCTZ ceramics under high direct-current voltage (DCV).

scholarly journals Enhancing the photocatalytic hydrogen production activity of BiVO4 [110] facets using oxygen vacancies

RSC Advances ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 540-545
Author(s):  
Jing Pan ◽  
Xiaoxue Ma ◽  
Wannian Zhang ◽  
Jingguo Hu
Keyword(s):  
Hydrogen Production ◽  
Oxygen Vacancy ◽  
Electric Field ◽  
Oxygen Vacancies ◽  
Internal Electric Field ◽  
Photocatalytic Hydrogen Production ◽  
Production Activity

An oxygen-vacancy-induced internal electric field enhances the photocatalytic hydrogen production activity of a BiVO4 [110] facet.

scholarly journals Precise Control of Surface Oxygen Vacancies in ZnO Nanoparticles for Extremely High Acetone Sensing Response

2021 ◽  
Author(s):  
Jihyun Lee ◽  
Youngmoon Choi ◽  
Byoung Joon Park ◽  
Jeong Woo Han ◽  
Hyun-Sook Lee ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Oxygen Vacancies ◽  
Surface Defects ◽  
High Sensitivity ◽  
Fast Response ◽  
Oxide Semiconductor ◽  
Surface Oxygen ◽  
Zno Nps ◽  
Precise Control ◽  
Optimal Surface

Abstract ZnO has been studied intensely for chemical sensors due to its high sensitivity and fast response. Here, we present a simple approach to precisely control oxygen vacancy contents to provide significantly enhanced acetone sensing performance of commercial ZnO nanopowders. A combination of H2O2 treatment and thermal annealing produces optimal surface defects with oxygen vacancies on the ZnO nanoparticles (NPs). The highest response of ~27,562 was achieved for 10 ppm acetone in 0.125 M H2O2 treated/annealed ZnO NPs at the optimal working temperature of 400 ℃, which is significantly higher than that of reported so far in various acetone sensors based on metal-oxide-semiconductor (MOS). Furthermore, first-principles calculations indicate that pre-adsorbed O formed on the surface of H2O2-treated ZnO NPs can provide a favorable adsorption energy, especially for acetone detection, due to strong bidentate bonding between carbonyl C atom of acetone molecules and pre-adsorbed O on the ZnO surface. Our study demonstrates that controlling surface oxygen vacancies by H2O2 treatment and re-annealing at optimal temperature is an effective method to improve the sensing properties of commercial MOS materials.

MECHANISM STUDY ON OXYGEN VACANCY INDUCED RESISTANCE SWITCHING IN Au/LaMnO3/SrNb0.01Ti0.99O3

2013 ◽  
Vol 27 (11) ◽  
pp. 1350074 ◽  
Author(s):  
YU-LING JIN ◽  
ZHONG-TANG XU ◽  
KUI-JUAN JIN ◽  
CHEN GE ◽  
HUI-BIN LU ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Oxygen Vacancies ◽  
Vacancy Concentration ◽  
Resistance Switching ◽  
Switching Behavior ◽  
Oxygen Vacancy Concentration ◽  
Mechanism Study ◽  
Switching Performance ◽  
Switching Characteristics

Mechanism of resistance switching in heterostructure Au / LaMnO 3/ SrNb 0.01 Ti 0.99 O 3 was investigated. In Au / LaMnO 3/ SrNb 0.01 Ti 0.99 O 3 devices the LaMnO 3 films were fabricated under various oxygen pressures. The content of the oxygen vacancies has a significant impact on the resistance switching performance. We propose that the resistance switching characteristics of Au / LaMnO 3/ SrNb 0.01 Ti 0.99 O 3 arise from the modulation of the Au / LaMnO 3 Schottky barrier due to the change of the oxygen vacancy concentration at Au / LaMnO 3 interface under the external electric field. The effect of the oxygen vacancy concentration on the resistance switching is explained based on the self-consistent calculation. Both the experimental and numerical results confirm the important role of the oxygen vacancies in the resistance switching behavior.

Structural and Electronic Properties of Oxygen Vacancies in Monoclinic HfO2

2007 ◽  
Vol 996 ◽  
Author(s):  
Peter Broqvist ◽  
Alfredo Pasquarello
Keyword(s):  
Oxygen Vacancy ◽  
Optical Absorption ◽  
Total Energy ◽  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Structural And Electronic Properties ◽  
Defect Levels ◽  
Hybrid Density Functional

AbstractWe study structural and electronic properties of the oxygen vacancy in monoclinic HfO2 for five different charge states. We use a hybrid density functional to accurately reproduce the experimental band gap. To compare with measured defect levels, we determine total-energy differences appropriate to the considered experiments. Our results show that the oxygen vacancy can consistently account for the defect levels observed in optical absorption, direct electron injection, and trap-assisted conduction experiments.

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