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.

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-confined CoMoO4@CoNiO2 nanorod arrays for oxygen evolution with improved performance

2019 ◽  
Vol 48 (27) ◽  
pp. 10116-10121 ◽  
Author(s):  
Xiaoqiang Du ◽  
Guangyu Ma ◽  
Xiaoshuang Zhang
Keyword(s):  
Oxygen Vacancy ◽  
Oxygen Evolution ◽  
Adsorption Energy ◽  
Active Sites ◽  
Oxygen Vacancies ◽  
Dft Calculation ◽  
Catalytic Properties ◽  
Nanorod Arrays ◽  
Calculation Results ◽  
Improved Performance

Experimental and DFT calculation results show that the presence of oxygen vacancies can decrease the adsorption energy of intermediates at active sites and facilitate the adsorption of intermediates, thus improving the catalytic properties.

scholarly journals Noble-Metal-Free NixSy-C3N5 Hybrid Nanosheet with Highly Efficient Photocatalytic Performance

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1089
Author(s):  
Lixiao Han ◽  
Cong Peng ◽  
Jinming Huang ◽  
Linhao Sun ◽  
Shengyao Wang ◽  
...  
Keyword(s):  
Noble Metal ◽  
Active Sites ◽  
Photocatalytic Performance ◽  
Low Cost ◽  
H2 Production ◽  
Apparent Quantum Yield ◽  
Metal Free ◽  
Highly Efficient ◽  
Multifunctional Catalyst ◽  
Photocatalytic Applications

The construction of highly efficient, low-cost and noble-metal-free photocatalysts depends on photocatalytic technology. Recently, N-rich C3N5 has been explored as a novel carbon nitride material with a much narrower band gap (~2.2 eV) than that of traditional C3N4 (~2.7 eV). Planting noble-metal-free active sites on C3N5 to improve its photocatalytic activity is of great significance. Herein, 2D NixSy nanosheet is facially loaded on 2D C3N5 using a hydrothermal procedure under a low temperature. Due to the quick separation of photogenerated carries between C3N5 and NixSy, this inexpensive noble-metal-free NixSy-C3N5 hybrid nanosheet is highly efficient and stable as a multifunctional catalyst in various applications, including photocatalytic H2 production from water and NO removal. Impressively, the apparent quantum yield (AQY) value for H2 production reaches 37.0% (at 420 nm) on optimal NixSy-C3N5 hybrids, which is much higher than that of Pt-C3N5 material. This work opens an avenue to the fabrication of low-cost and noble-metal-free catalysts for multifunctional photocatalytic applications.

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.

scholarly journals Enhanced Hydrogen Production from Ethanol Photoreforming by Site-Specific Deposition of Au on Cu2O/TiO2 p-n Junction

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 539
Author(s):  
Lan Luo ◽  
Tingting Zhang ◽  
Xin Zhang ◽  
Rongping Yun ◽  
Yanjun Lin ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Active Sites ◽  
Oxygen Vacancies ◽  
Au Nanoparticles ◽  
H2 Production ◽  
Site Specific ◽  
Tio2 Catalyst ◽  
Simulated Solar Light ◽  
A Site ◽  
Dehydrogenation Of Ethanol

Hydrogen production by photoreforming of biomass-derived ethanol is a renewable way of obtaining clean fuel. We developed a site-specific deposition strategy to construct supported Au catalysts by rationally constructing Ti3+ defects inTiO2 nanorods and Cu2O-TiO2 p-n junction across the interface of two components. The Au nanoparticles (~2.5 nm) were selectively anchored onto either TiO2 nanorods (Au@TiO2/Cu2O) or Cu2O nanocubes (Au@Cu2O/TiO2) or both TiO2 and Cu2O (Au@TiO2/Cu2O@Au) with the same Au loading. The electronic structure of supported Au species was changed by forming Au@TiO2 interface due to the adjacent Ti3+ defects and the associated oxygen vacancies while unchanged in Au@Cu2O/TiO2 catalyst. The p-n junction of TiO2/Cu2O promoted charge separation and transfer across the junction. During ethanol photoreforming, Au@TiO2/Cu2O catalyst possessing both the Au@TiO2 interface and the p-n junction showed the highest H2 production rate of 8548 μmol gcat−1 h−1 under simulated solar light, apparently superior to both Au@TiO2 and Au@Cu2O/TiO2 catalyst. The acetaldehyde was produced in liquid phase at an almost stoichiometric rate, and C−C cleavage of ethanol molecules to form CH4 or CO2 was greatly inhibited. Extensive spectroscopic results support the claim that Au adjacent to surface Ti3+ defects could be active sites for H2 production and p-n junction of TiO2/Cu2O facilitates photo-generated charge transfer and further dehydrogenation of ethanol to acetaldehyde during the photoreforming.

scholarly journals Study on the adsorption selection of CH$$_4$$ on CuO (110) versus (111) surfaces: a density functional theory study

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Long Lin ◽  
Linwei Yao ◽  
Shaofei Li ◽  
Zhengguang Shi ◽  
Kun Xie ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Adsorption Capacity ◽  
Active Sites ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Density Functional Theory Calculations ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Strong Adsorption ◽  
Selection Of

AbstractFinding the active sites of suitable metal oxides is a key prerequisite for detecting CH$$_4$$ 4 . The purpose of the paper is to investigate the adsorption of CH$$_4$$ 4 on intrinsic and oxygen-vacancies CuO (111) and (110) surfaces using density functional theory calculations. The results show that CH$$_4$$ 4 has a strong adsorption energy of −0.370 to 0.391 eV at all site on the CuO (110) surface. The adsorption capacity of CH$$_4$$ 4 on CuO (111) surface is weak, ranging from −0.156 to −0.325 eV. In the surface containing oxygen vacancies, the adsorption capacity of CuO surface to CH$$_4$$ 4 is significantly stronger than that of intrinsic CuO surface. The results indicate that CuO (110) has strong adsorption and charge transfer capacity for CH$$_4$$ 4 , which may provide experimental guidance.

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.

Sign in / Sign up

Export Citation Format

Share Document