scholarly journals Greatly improved adsorption and degradation by S-doped (001)-TiO2 via the vapour-thermal method

2019 ◽  
Author(s):  
X Y Sun ◽  
X Zhang ◽  
X Sun ◽  
N X Qian ◽  
Min Wang ◽  
...  
Keyword(s):  
Degradation Rate ◽  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
Lattice Distortion ◽  
Synergistic Effects ◽  
Molar Ratio ◽  
Thermal Method ◽  
Adsorption Coefficient ◽  
Ionic Radii ◽  
Chemical States

In this work, sulfur (S) doped (001)-face exposed TiO2 was synthesized via the vapor-thermal method at 180 °C or 250 °C, with an S/Ti molar ratio R S/Ti of 0, 0.5, 1, 2, 3, 4, and 5. The S-doped samples at 250 °C exhibited significantly improved photocatalytic performance. The effects of S doping were as follows: (1) The S element exhibits different chemical states in the samples with different R S/Ti. Specifically, it exists in the form of S2− replacing O2− at R S/Ti = 1, and S6+ replacing Ti4+ at R S/Ti ≥ 2. As a result, S doping causes a lattice distortion because the ionic radii of S2− and S6+ differ from that of the O2− and Ti4+. (2) S-doping increases the adsorption coefficient A e for methylene blue (MB) from 0.9% to 68.5% due to the synergistic effects of the oxygen vacancies, the SO4 2− adsorbed on the TiO2 surface, and the pore size. (3) S-doping increases the MB degradation rate from 6.9 × 10−2 min−1 to 18.2 × 10−2 min−1 due to an increase in the amount of •OH and •O2− radicals.

scholarly journals Improved adsorption and degradation performance by S-doping of (001)-TiO2

2019 ◽  
Vol 10 ◽  
pp. 2116-2127 ◽  
Author(s):  
Xiao-Yu Sun ◽  
Xiao Sun ◽  
Xian Zhang ◽  
Ni-Xian Qian ◽  
Min Wang ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
Lattice Distortion ◽  
Synergistic Effects ◽  
Chemical Vapor ◽  
Surface Chemical ◽  
Ionic Radii ◽  
Thermal Chemical Vapor Deposition ◽  
Molar Ratios ◽  
Chemical States

In this work, sulfur-doped (S-doped) TiO2 with the (001) face exposed was synthesized by thermal chemical vapor deposition at 180 or 250 °C using S/Ti molar ratios R S/Ti of 0, 0.5, 1, 2, 3, 4 and 5. The S-doped samples synthesized at 250 °C exhibit a significantly improved photocatalytic performance. More precisely, S-doping has the following effects on the material: (1) S can adopt different chemical states in the samples. Specifically, it exists in the form of S2− replacing O2− at a ratio of R S/Ti = 1 and also in the form of S6+ replacing Ti4+ at R S/Ti ≥ 2. As a result, S-doping causes a lattice distortion, because the ionic radii of S2− and S6+ differ from that of the O2− and Ti4+ ions. (2) S-doping increases the adsorption coefficient A e for methylene blue (MB) from 0.9% to 68.5% due to the synergistic effects of the oxygen vacancies, increased number of surface chemical adsorption centers as a result of SO4 2− adsorption on the TiO2 surface and the larger pore size. (3) S-doping increases the MB degradation rate from 6.9 × 10−2 min−1 to 18.2 × 10−2 min−1 due to an increase in the amount of •OH and •O2− radicals.

Graphene oxide mediated co-generation of C-doping and oxygen defects in Bi2WO6 nanosheets: a combined DRIFTS and DFT investigation

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20562-20570 ◽  
Author(s):  
Minglu Sun ◽  
Xing'an Dong ◽  
Ben Lei ◽  
Jieyuan Li ◽  
Peng Chen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Hydrothermal Method ◽  
Oxygen Vacancies ◽  
Photocatalytic Performance ◽  
Synergistic Effects ◽  
No Removal ◽  
Oxygen Defects ◽  
C Doping

The co-generation of C-doping and oxygen vacancies (OVs) in Bi2WO6 nanosheets was achieved by a graphene oxide-mediated hydrothermal method. The photocatalytic performance was highly promoted in NO removal with the synergistic effects of C-doping and OVs.

Magnetic Composite Fe3O4/CuO/TiO2 Nanoparticles: Preparation, Characterization and Photocatalytic Activity

2015 ◽  
Vol 827 ◽  
pp. 13-18 ◽  
Author(s):  
Shofianina Jalaludin ◽  
Sarah A. Arifin ◽  
Rosari Saleh
Keyword(s):  
Methylene Blue ◽  
Degradation Rate ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Cuo Nanoparticles ◽  
Composite Nanoparticles ◽  
Molar Ratio ◽  
Magnetic Composite ◽  
Photocatalytic Efficiency ◽  
Structure Morphology

Magnetic composite Fe3O4/TiO2/CuO nanoparticles have been synthesized by sol-gel method at low temperature. The resultant composite nanoparticles coupled with different Cu contained by adjusting the molar ratio of CuO to (Fe3O4/TiO2) from 1:1 – 5:1. The structure, morphology and properties of nanoparticles were characterized using XRD, EDX, FESEM and VSM. The results showed that all composite nanoparticles consist of cubic spinel Fe3O4, anatase TiO2 and monoclinic CuO, have ferromagnetic properties. The photocatalytic performance was evaluated using methylene blue in aqueous solutions under UV and visible light irradiation. Among the composite Fe3O4/TiO2/CuO nanoparticles, the sample with the molar ratio of CuO to (Fe3O4/TiO2) = 5 : 1 exhibited the highest photocatalytic efficiency. Photocatalytic mechanism was investigated by measuring the photocatalytic degradation rate in the presence of scavenger. The results suggested that holes play the most important role in degradation of methylene blue.

scholarly journals The Catalytic Oxidation of Formaldehyde by FeOx-MnO2-CeO2 Catalyst: Effect of Iron Modification

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 555
Author(s):  
Yaxin Dong ◽  
Chenguang Su ◽  
Kai Liu ◽  
Haomeng Wang ◽  
Zheng Zheng ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Oxygen Vacancies ◽  
Catalytic Performance ◽  
Active Oxygen ◽  
Molar Ratio ◽  
N2 Adsorption ◽  
Structure Activity ◽  
Iron Modification ◽  
Surface Active ◽  
Catalyst Effect

A series of FeOx-MnO2-CeO2 catalysts were synthesized by the surfactant-templated coprecipitation method and applied for HCHO removal. The influence of Fe/Mn/Ce molar ratio on the catalytic performance was investigated, and the FeOx-MnO2-CeO2 catalyst exhibited excellent catalytic activity, with complete HCHO conversion at low temperatures (40 °C) when the molar ratio of Fe/Mn/Ce was 2/5/5. The catalysts were characterized by N2 adsorption and desorption, XRD, H2-TPR, O2-TPD and XPS techniques to illustrate their structure–activity relationships. The result revealed that the introduction of FeOx into MnO2-CeO2 formed a strong interaction between FeOx-MnO2-CeO2, which facilitated the improved dispersion of MnO2-CeO2, subsequently increasing the surface area and aiding pore development. This promotion effect of Fe enhanced the reducibility and produced abundant surface-active oxygen. In addition, a great number of Oα is beneficial to the intermediate decomposition, whereas the existence of Ce3+ favors the formation of oxygen vacancies on the surface of the catalyst, all of which contributed to HCHO oxidation at low temperatures.

Morphology-dependent oxygen vacancies and synergistic effects of Ni/CeO2 catalysts for N2O decomposition

2018 ◽  
Vol 8 (1) ◽  
pp. 276-288 ◽  
Author(s):  
Pei Zhao ◽  
Feng Qin ◽  
Zhen Huang ◽  
Chao Sun ◽  
Wei Shen ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Synergistic Effects ◽  
N2o Decomposition ◽  
Vital Effects

Strong morphology-dependent oxygen vacancies and synergistic effects of Ni/CeO2 catalysts and their vital effects on N2O decomposition.

The Study on the Influential Factors of Photocatalytic Performance of Eosin-Sensitized TiO2 Nanoparticles

2013 ◽  
Vol 827 ◽  
pp. 3-7
Author(s):  
Shun Jiang He ◽  
Xue Yan Du ◽  
Qiao Wang ◽  
Jing Xu
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Degradation Rate ◽  
Photocatalytic Performance ◽  
Influential Factors ◽  
Sunlight Irradiation ◽  
Sensitization Time

The photocatalytic activity of eosin-sensitized TiO2 nanoparticles on photocatalytic degradation rate (PDR) of methyl orange under sunlight irradiation was studied. The influential factors on the degradation, such as eosin concentration, TiO2 dosage, sensitization time and sensitization temperature were also investigated. The results show that: The performance of TiO2 nanoparticles for PDR of methyl orange has been improved obviously for eosin sensitizing. The PDR of methyl orange reached 45.28% under the conditions of eosin concentration of 20mg/L, TiO2 dosage of 0.5000g/L, sensitization time of 24h and sensitization temperature of 20°C.

Synergistic effects of oxygen vacancies and the chelation of tetracycline with metallic ions for enhanced degradation of tetracycline over photocatalysts La2-xKxNiMnO6

CrystEngComm ◽  
2021 ◽  
Author(s):  
Xiaoyan Yu ◽  
Ke Lu ◽  
Le Chen
Keyword(s):  
Oxygen Vacancies ◽  
Synergistic Effects ◽  
Metallic Ions ◽  
Photogenerated Electrons ◽  
Enhanced Degradation

Oxygen vacancies (OVs) can trap photogenerated electrons (e－) to promot the separation of photogenerated e－ and holes ( h＋), and can serve as the reactive sites in a variety of...

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.

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