scholarly journals Enhanced Photocatalytic Activation of Methane C-H Bond by Incorporate Cerium into ETS-10

2020 ◽  
Author(s):  
Yang Cao
Keyword(s):  
Rare Earth ◽  
Visible Light ◽  
Methane Conversion ◽  
Atomic Scale ◽  
Charge Hole ◽  
Electron Hole ◽  
Strong Electron ◽  
Conversion Reaction ◽  
Ce Modification ◽  
Conversion Performance

<p>Ce-ETS-10 was prepared and their ability on photocatalysis coupling of methane has been studied in detail. Ce modification enhanced the photocatalysis performance of ETS-10 on methane conversion reaction, and the methane conversion can be carried out under irradiation of visible light. To study the various rare earth modification to ETS-10, various rare earth elements were introduced to ETS-10 molecular sieve, and the relative photocatalytic methane conversion performance were studied. Various characterizations were applied to examine rare earth modification behavior. The SPS results show that the Cerium modification induce visible light photovoltage, which means the strong electron-hole separation which enhance the photocatalytic performance. The charge-hole separation is non-traditional n-n heterojunction for the charge-hole separation is highly oriented and efficient at atomic scale. This mechanism shows significant enhancement for methane conversion reaction. </p>

scholarly journals Enhanced Photocatalytic Activation of Methane C-H Bond by Incorporate Cerium into ETS-10

2020 ◽  
Author(s):  
Yang Cao
Keyword(s):  
Rare Earth ◽  
Visible Light ◽  
Methane Conversion ◽  
Atomic Scale ◽  
Charge Hole ◽  
Electron Hole ◽  
Strong Electron ◽  
Conversion Reaction ◽  
Ce Modification ◽  
Conversion Performance

<p>Ce-ETS-10 was prepared and their ability on photocatalysis coupling of methane has been studied in detail. Ce modification enhanced the photocatalysis performance of ETS-10 on methane conversion reaction, and the methane conversion can be carried out under irradiation of visible light. To study the various rare earth modification to ETS-10, various rare earth elements were introduced to ETS-10 molecular sieve, and the relative photocatalytic methane conversion performance were studied. Various characterizations were applied to examine rare earth modification behavior. The SPS results show that the Cerium modification induce visible light photovoltage, which means the strong electron-hole separation which enhance the photocatalytic performance. The charge-hole separation is non-traditional n-n heterojunction for the charge-hole separation is highly oriented and efficient at atomic scale. This mechanism shows significant enhancement for methane conversion reaction. </p>

scholarly journals Construction of Ag3PO4/SnO2 Heterojunction on Carbon Cloth with Enhanced Visible Light Photocatalytic Degradation

2020 ◽  
Vol 10 (9) ◽  
pp. 3238
Author(s):  
Min Liu ◽  
Guangxin Wang ◽  
Panpan Xu ◽  
Yanfeng Zhu ◽  
Wuhui Li
Keyword(s):  
Visible Light ◽  
Photocatalytic Performance ◽  
Separation Efficiency ◽  
Photogenerated Electron ◽  
Carbon Cloth ◽  
Electron Hole ◽  
Step Process ◽  
Photogenerated Electrons ◽  
Rapid Transfer ◽  
Visible Light Photocatalytic

In this study, the Ag3PO4/SnO2 heterojunction on carbon cloth (Ag3PO4/SnO2/CC) was successfully fabricated via a facile two-step process. The results showed that the Ag3PO4/SnO2/CC heterojunction exhibited a remarkable photocatalytic performance for the degradation of Rhodamine B (RhB) and methylene blue (MB), under visible light irradiation. The calculated k values for the degradation of RhB and MB over Ag3PO4/SnO2/CC are 0.04716 min−1 and 0.04916 min−1, which are higher than those calculated for the reactions over Ag3PO4/SnO2, Ag3PO4/CC and SnO2/CC, respectively. The enhanced photocatalytic activity could mainly be attributed to the improved separation efficiency of photogenerated electron-hole pairs, after the formation of the Ag3PO4/SnO2/CC heterojunction. Moreover, carbon cloth with a large specific surface area and excellent conductivity was used as the substrate, which helped to increase the contact area of dye solution with photocatalysts and the rapid transfer of photogenerated electrons. Notably, when compared with the powder catalyst, the catalysts supported on carbon cloth are easier to quickly recycle from the pollutant solution, thereby reducing the probability of recontamination.

scholarly journals Enhanced Visible-Light Photocatalytic Performance of SAPO-5-Based g-C3N4 Composite for Rhodamine B (RhB) Degradation

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3948
Author(s):  
Lingfang Qiu ◽  
Zhiwei Zhou ◽  
Mengfan Ma ◽  
Ping Li ◽  
Jinyong Lu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Redox Reactions ◽  
Photocatalytic Performance ◽  
Dye Degradation ◽  
Thermal Polymerization ◽  
Light Illumination ◽  
Electron Hole ◽  
Visible Light Illumination ◽  
Visible Light Photocatalytic

Novel visible-light responded aluminosilicophosphate-5 (SAPO-5)/g-C3N4 composite has been easily constructed by thermal polymerization for the mixture of SAPO-5, NH4Cl, and dicyandiamide. The photocatalytic activity of SAPO-5/g-C3N4 is evaluated by degrading RhB (30 mg/L) under visible light illumination (λ > 420 nm). The effects of SAPO-5 incorporation proportion and initial RhB concentration on the photocatalytic performance have been discussed in detail. The optimized SAPO-5/g-C3N4 composite shows promising degradation efficiency which is 40.6% higher than that of pure g-C3N4. The degradation rate improves from 0.007 min−1 to 0.022 min−1, which is a comparable photocatalytic performance compared with other g-C3N4-based heterojunctions for dye degradation. The migration of photo-induced electrons from g-C3N4 to the Al site of SAPO-5 should promote the photo-induced electron-hole pairs separation rate of g-C3N4 efficiently. Furthermore, the redox reactions for RhB degradation occur on the photo-induced holes in the g-C3N4 and Al sites in SAPO-5, respectively. This achievement not only improves the photocatalytic activity of g-C3N4 efficiently, but also broadens the application of SAPOs in the photocatalytic field.

scholarly journals Preparation and Photocatalytic Performance for Degradation of Rhodamine B of AgPt/Bi4Ti3O12 Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2206
Author(s):  
Gaoqian Yuan ◽  
Gen Zhang ◽  
Kezhuo Li ◽  
Faliang Li ◽  
Yunbo Cao ◽  
...  
Keyword(s):  
Visible Light ◽  
Noble Metal ◽  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Bimetallic Nanoparticles ◽  
Resonance Effect ◽  
Visible Region ◽  
Photogenerated Electron ◽  
Pt Nanoparticles ◽  
Electron Hole

Loading a noble metal on Bi4Ti3O12 could enable the formation of the Schottky barrier at the interface between the former and the latter, which causes electrons to be trapped and inhibits the recombination of photoelectrons and photoholes. In this paper, AgPt/Bi4Ti3O12 composite photocatalysts were prepared using the photoreduction method, and the effects of the type and content of noble metal on the photocatalytic performance of the catalysts were investigated. The photocatalytic degradation of rhodamine B (RhB) showed that the loading of AgPt bimetallic nanoparticles significantly improved the catalytic performance of Bi4Ti3O12. When 0.10 wt% noble metal was loaded, the degradation rate for RhB of Ag0.7Pt0.3/Bi4Ti3O12 was 0.027 min−1, which was respectively about 2, 1.7 and 3.7 times as that of Ag/Bi4Ti3O12, Pt/Bi3Ti4O12 and Bi4Ti3O12. The reasons may be attributed as follows: (i) the utilization of visible light was enhanced due to the surface plasmon resonance effect of Ag and Pt in the visible region; (ii) Ag nanoparticles mainly acted as electron acceptors to restrain the recombination of photogenerated electron-hole pairs under visible light irradiation; and (iii) Pt nanoparticles acted as electron cocatalysts to further suppress the recombination of photogenerated electron-hole pairs. The photocatalytic performance of Ag0.7Pt0.3/Bi4Ti3O12 was superior to that of Ag/Bi4Ti3O12 and Pt/Bi3Ti4O12 owing to the synergistic effect between Ag and Pt nanoparticles.

scholarly journals Microstructure and Photothermal Conversion Performance of Ti/(Mo-TiAlN)/(Mo-TiAlON)/Al2O3 Selective Absorbing Film for Non-Vacuum High-Temperature Applications

2020 ◽  
Vol 11 (1) ◽  
pp. 124
Author(s):  
Haibin Geng ◽  
Hanzhe Ye ◽  
Xingliang Chen ◽  
Sibin Du
Keyword(s):  
Visible Light ◽  
Near Infrared ◽  
Substitutional Solid Solution ◽  
Experimental Conditions ◽  
Al Content ◽  
Spectrum Range ◽  
Light Interference ◽  
Transmission Electron ◽  
Conversion Performance ◽  
Columnar Grain

This paper aims to clarify the phase composition in each sub-layer of tandem absorber TiMoAlON film and verify its thermal stability. The deposited multilayer Ti/(Mo-TiAlN)/(Mo-TiAlON)/Al2O3 films include an infrared reflectance layer, light interference absorptive layers with different metal doping amounts, and an anti-reflectance layer. The layer thicknesses of Ti, Mo-TiAlN, Mo-TiAlON, and Al2O3 are 100, 300, 200, and 80 nm, respectively. Al content increases to 12 at.% and the ratio of N/O is nearly 0.1, which means nitride continuously changes to oxide. According to X-ray Diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) results, the diffraction peak that appears at 2θ = 40° demonstrates that Mo element aggregates in the substitutional solid solution (Ti,Al)(O,N) columnar grain. TiMoAlON films have low reflectivity in the spectrum range of 300–900 nm. When Al content is more than 10 at.%, absorptivity is almost in the spectrum range from visible to infrared, but absorptivity decreases in the ultraviolet spectrum range. When Al content is increased to 12 at.%, absorptivity α decreases by 0.05 in the experimental conditions. After baking in atmosphere at 500 °C for 8 h, the film has the highest absorptivity when doped with 2 at.% Mo. In the visible-light range, α = 0.97, and in the whole ultraviolet-visible-light near-infrared spectrum range, α = 0.94, and emissivity ε = 0.02 at room temperature and ε = 0.10 at 500 °C.

scholarly journals Magnetic Field-Assisted Photocatalytic Degradation of Organic Pollutants over Bi1−xRxFeO3 (R = Ce, Tb; x = 0.00, 0.05, 0.10 and 0.15) Nanostructures

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4079
Author(s):  
Radhalayam Dhanalakshmi ◽  
Nambi Venkatesan Giridharan ◽  
Juliano C. Denardin
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Organic Pollutants ◽  
Visible Light Irradiation ◽  
Organic Pollutant ◽  
Hydrothermal Process ◽  
Phenol Red ◽  
Magnetic Features

Magnetic-field-accelerated photocatalytic degradation of the phenol red (PR) as a model organic pollutant was studied using rare-earth elements modified BiFeO3 (Bi1−xRxFeO3 (R = Ce, Tb; x = 0.0, 0.05, 0.10 and 0.15); BFO: RE) nanostructures. The nanostructures were prepared via the hydrothermal process and their morphological, structural, functional, optical and magnetic features were investigated in detail. The effect of magnetic fields (MFs) on photocatalysis were examined by applying the different MFs under visible light irradiation. The enhanced photodegradation efficiencies were achieved by increasing the MF up to 0.5T and reduced at 0.7T for the compositions x = 0.10 in both Ce and Tb substituted BFO. Further, mineralization efficiencies of PR, reproducibility of MF-assisted photocatalysis, stability and recyclability of BFO: RE nanostructures were also tested.

Hidden Nature of the Conversion Reaction from Rare Earth Chloride to Oxychloride and the Application to Novel Separation

2018 ◽  
Vol 3 (11) ◽  
pp. 2998-3002
Author(s):  
Hiroki Yamamoto ◽  
Motoyuki Miyata ◽  
Hajime Murakami ◽  
Katsuyoshi Furusawa ◽  
Tetsuya Uda
Keyword(s):  
Rare Earth ◽  
Conversion Reaction ◽  
Rare Earth Chloride

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

Enhanced visible-active photocatalytic behaviors observed in Mn-doped BiFeO3

2018 ◽  
Vol 32 (17) ◽  
pp. 1850185 ◽  
Author(s):  
Yun-Hui Si ◽  
Yu Xia ◽  
Ya-Yun Li ◽  
Shao-Ke Shang ◽  
Xin-Bo Xiong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Mn Doped ◽  
Hole Recombination ◽  
Narrow Band Gap Semiconductors

A series of BiFeO3 and BiFe[Formula: see text]Mn[Formula: see text]O3 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by a hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS) and UV–Vis diffuse reflectance spectroscopy, and their photocatalytic activity was studied by photocatalytic degradation of methylene blue in aqueous solution under visible light irradiation. The band gap of BiFeO3 was significantly decreased from 2.26 eV to 1.90 eV with the doping of Mn. Furthermore, the 6% Mn-doped BiFeO3 photocatalyst exhibited the best activity with a degradation rate of 94% after irradiation for 100 min. The enhanced photocatalytic activity with Mn doping could be attributed to the enhanced optical absorption, increment of surface reactive sites and reduction of electron–hole recombination. Our results may be conducive to design more efficient photocatalysts responsive to visible light among narrow band gap semiconductors.

scholarly journals Synthesis, Analysis, and Testing of BiOBr-Bi2WO6Photocatalytic Heterojunction Semiconductors

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Xiangchao Meng ◽  
Zisheng Zhang
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Degradation Process ◽  
Light Irradiation ◽  
Enhancement Effect ◽  
Electron Hole ◽  
Experimental Conditions ◽  
Synthesis Conditions ◽  
Optimum Synthesis ◽  
Photocatalytic Activities

In photocatalysis, the recombination of electron-hole pairs is generally regarded as one of its most serious drawbacks. The synthesis of various composites with heterojunction structures has increasingly shed light on preventing this recombination. In this work, a BiOBr-Bi2WO6photocatalytic heterojunction semiconductor was synthesized by the facile hydrothermal method and applied in the photocatalytic degradation process. It was determined that both reaction time and temperature significantly affected the crystal structure and morphologies of the photocatalysts. BiOBr (50 at%)-Bi2WO6composites were prepared under optimum synthesis conditions (120°C for 6 h) and by theoretically analyzing the DRS results, it was determined that they possessed the suitable band gap (2.61 eV) to be stimulated by visible-light irradiation. The photocatalytic activities of the as-prepared photocatalysts were evaluated by the degradation ofRhodamine B (RhB)under visible-light irradiation. The experimental conditions, including initial concentration, pH, and catalyst dosage, were explored and the photocatalysts in this system were proven stable enough to be reused for several runs. Moreover, the interpreted mechanism of the heterojunction enhancement effect proved that the synthesis of a heterojunction structure provided an effective method to decrease the recombination rate of the electron-hole pairs, thereby improving the photocatalytic activity.

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