Search query: “Photocatalytic” and “Bi2Fe4O9”

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abstract: Abstract Herein, Bi2Fe4O9 nanoplates (BFO NPs) with controllable thickness are successfully synthesized via a facile hydrothermal method with varied content of sodium dodecyl benzene sulfonate (SDBS) The thickness along the [001] direction of the BFO NPs can be controlled by varying the SDBS content, and the decreased thickness plays multiple roles in improving the photocatalytic water oxidation performance: (1) increasing the distortion and asymmetries of the FeO4 tetrahedral and FeO6 octahedral units, and enhancing the built in electric field in the BFO NPs accordingly, to facilitate the efficient separation of photogenerated electron hole pairs; (2) reducing the migration distance of holes to the surface of the both oxygen and bismuth enriched {001} facets; (3) promoting the exposure of {001} facets of the BFO NPs which facilitates hole accumulation and provides more active sites to accelerate surface oxidation reaction. As a result, the as prepared BFO 2 sample with optimized thickness exhibits the best photocatalytic water oxidation performance under visible light irradiation, achieving the O2 evolution rate of 461.08 umol g 1 h 1, about 7.87 times higher than BFO NPs prepared without using SDBS. The built in electric field for BFO and its role in photocatalytic water oxidation process are reported for the first time. This work provides new insights into improving intrinsic activity of individual semiconductor photocatalyst by morphology and structure modulation and charge behavior regulation.
author_names: Huan-huan Liu

Lipei Li

Changfa Guo

Jiqiang Ning

Yijun Zhong

Yong Hu
title: Thickness dependent carrier separation in Bi2Fe4O9 nanoplates with enhanced photocatalytic water oxidation
year: 2020

abstract: Abstract Graphitic carbon nitride (g C3N4) with fluorine (F) doping was synthesized by a hydrothermal technique, and F doped g C3N4/Bi2Fe4O9 composites were synthesized by electrostatic self assembly technique. The crystal structures were studied by X ray diffraction, the morphology was determined by transmission electron microscope images, and the F doping was verified by energy dispersive X ray analysis, Fourier transform infrared spectroscopy, and X ray photoelectron spectroscopy. The N2 adsorption/desorption results showed that introducing Bi2Fe4O9 nanoparticles into F doped g C3N4 reduced the specific surface area and volume of the pores. This could be attributed to the Bi2Fe4O9 nanoparticles partially blocking the pores of F doped g C3N4. The photocatalytic performance of F doped g C3N4/Bi2Fe4O9 composites was studied by oxidizing NO under visible irradiation. The photocatalytic performance indicated that the presence of Bi2Fe4O9 increased the photocatalytic activity of F doped g C3N4 by up to ~100% The increased photocatalytic performance could be ascribed to a decreased combination rate of the charge carriers. Moreover, scavenger testing study showed that the reactive species, including h+ O2, and *O2 played important roles in the photocatalytic reactions.
author_names: Huazhong Liu

Xiaolan Wang

Han Xu

Chunxia Luo
title: Facile synthesis of F doped g C3N4/Bi2Fe4O9 heterostructure with Z scheme for enhanced photocatalytic performance in NO oxidation
year: 2020

abstract: Pure phase Bi2Fe4O9 microstructures have been successfully synthesized via a facile hydrothermal method without using any organic surfactants. It was found that the synthesis of micro cubes and micro plates of Bi2Fe4O9 can be controlled by adjusting the NaOH concentration from 6 M to 12 M, at 200 degC for 12 h, with an optimized Bi/Fe molar ratio of 2:1. With the increase of NaOH concentration, the morphology of the products developed from micro cubes with a lateral size of 1.5 mm to micro plates with a lateral size of 1 mm and a curved outline. Moreover, the as synthesized Bi2Fe4O9 micro cubes and micro plates were evaluated for the photocatalytic degradation of methylene blue (MB) under visible light irradiation. A 90% degradation of MB with a time of 120 min has been achieved by using Bi2Fe4O9 micro plates, where the first order k constant was determined to be 0.01883 min 1. In addition, these micro plates exhibit a typical ferromagnetic property at room temperature, offering an opportunity for efficient utilization and recycling via possible magnetic assisted separation of organic pollutants for photocatalytic degradation.
author_names: Si Min Yin

Wen Qian Li

Runrun Cheng

Y F Yuan

S Y Guo

Zhaohui Ren
title: Hydrothermal Synthesis, Photocatalytic and Magnetic Properties of Pure Phase Bi2Fe4O9 Microstructures
venue: Journal of Electronic Materials
year: 2020

abstract: A magnetic Bi2Fe4O9/Bi2MoO6 heterojunction was synthesized by a facile one pot solvothermal method, and the photodegradation performance was evaluated by degrading methylene blue (MB) and tetracycline hydrochloride (TC) Compared with pure Bi2MoO6 composite, the Bi2Fe4O9/Bi2MoO6 heterojunction with 10% Bi2Fe4O9 had much higher catalytic performance, which can degrade MB and TC completely within 150 and 180 min. The characterization results show that a p n heterojunction formed between Bi2Fe4O9 and Bi2MoO6. Combining with trapping experiments, a direct Z scheme mechanism was proposed to effectively separate photodegradable electron hole pairs at the Bi2Fe4O9/Bi2MoO6 heterojunction interface. Moreover, the obtained catalysts can be recovered easily from liquid system via the external magnet field due to the sufficient magnetism. After five recycles, no significant decrease on the degradation efficiency of MB and TC can be found show that BiFeMo 2 has excellent chemical stability in the application of organic pollutants degradation under visible light irradiation. Thus, the prepared Bi2Fe4O9/Bi2MoO6 catalyst has the advantages of high visible light catalytic activity, excellent chemical stability and magnetic separation, and has broad application prospects in environmental purification. A novel magnetic recoverable Bi2Fe4O9/Bi2MoO6 catalyst was facilely prepared. BiFeMo 2 sample showed a higher activities for MB and TC photodegradation under visible light irradiation due to formation of a p n heterojunction with high quality interface between Bi2Fe4O9 (220) and Bi2MoO6 (131) which can improve charge transfer effectively follow the Z scheme mechanism.
author_names: Huiming Zhang

He Bian

Haixia Zhang

Bin Xu

Caihong Wang

Lijuan Zhang

Dazhi Li

Fengxiang Wang
title: Magnetic Separable Bi2Fe4O9/Bi2MoO6 Heterojunctions in Z Scheme with Enhanced Visible Light Photocatalytic Activity for Organic Pollutant Degradation
venue: Catalysis Letters
year: 2020

abstract: An efficient binary Bi2Fe4O9/Bi2WO6 Z scheme heterojunction was fabricated through a facile hydrothermal route. The obtained Bi2Fe4O9/Bi2WO6 displays high catalytic activity for rhodamine B (RhB) photodegradation, and 100% of RhB was photodegraded by Bi2Fe4O9 (7%/Bi2WO6 within 90 min, which is much better than that by pure Bi2Fe4O9 and Bi2WO6. The effective photoinduced carrier separation, the broadened photoabsorption range, high oxidation capacity of hole, and the high reduction power of electron are in charge of the elevated catalytic activity because of the formed Z scheme system. In addition, the effects such as pollutant concentration, pH, inorganic anions, and water sources exerted on photocatalytic performance were also investigated, and the results suggest that Bi2Fe4O9/Bi2WO6 still possesses a high photocatalytic performance. The free radical trapping experiments and electron spin resonance spin trapping technology disclose that hole (h+ hydroxy radical *OH) and superoxide radical *O2 are cardinal active radicals in the catalytic system. In terms of the above experimental analysis, a possible photodegradation mechanism of the as fabricated photocatalyst is thoroughly elucidated. In addition, the possible RhB photodegradation pathway is also raised in the light of the analysis of liquid chromatography mass/mass spectrometry. In addition, Bi2Fe4O9/Bi2WO6 composite does not display dramatic reduction of the catalytic performance after five recycles. Thus, this study reveals that the as obtained Bi2Fe4O9/Bi2WO6 catalyst has a great prospect for the environmental purification.
author_names: Bisheng Li

Cui Lai

Guangming Zeng

Lei Qin

Huan Yi

Danlian Huang

Chengyun Zhou

Xigui Liu

Min Cheng

Piao Xu

Chen Zhang

Fanglong Huang

Shiyu Liu
title: Facile Hydrothermal Synthesis of Z Scheme Bi2Fe4O9/Bi2WO6 Heterojunction Photocatalyst with Enhanced Visible Light Photocatalytic Activity.
venue: ACS applied materials interfaces
year: 2018

abstract: Pure Bi25FeO40, Bi2Fe4O9, and different weight ratios of Bi25FeO40/Bi2Fe4O9 composite photocatalysts have been synthesized via a hydrothermal process combined with a mixing calcination method and evaluated as visible light responsive catalyst for the degradation of Rhodamine B (RhB) All the as prepared samples have been characterized by a range of techniques including X ray diffraction (XRD) Fourier transform infrared spectra (FT IR) UV vis absorption spectra (DSR) Field Emission Scanning Electron Microscope (FE SEM) Transmission electron microscope (TEM) and High resolution TEM (HRTEM) The XRD, FT IR, TEM and HRTEM results confirm that the composite only consists of Bi25FeO40 and Bi2Fe4O9. In the Bi25FeO40/Bi2Fe4O9 composites, closely contacted interfaces have been observed. Compared with the single phase Bi25FeO40 and Bi2Fe4O9, Bi25FeO40/Bi2Fe4O9 composites exhibit enhanced visible light responsive photocatalytic activities. The photocatalytic efficiency of optimized Bi25FeO40/Bi2Fe4O9 composite with Bi2Fe4O9 weight ratio of 30% is about 8.8 and 6.2 times higher than that of pure Bi25FeO40 and Bi2Fe4O9, respectively. On the basis of electronic energy band structure analysis, the active species trapping experiments and the electrochemical impedance spectrum (EIS) performance, a heterojunction type charge transfer mechanism interpreting the enhanced photocatalytic activities of the composite are proposed and discussed. In addition, the effects of different Bi25FeO40/Bi2Fe4O9 weight ratios and their geometry architecture on photocatalytic activities are also thoroughly discussed.
author_names: Geming Wang

Da Cheng

Tiancheng He

Yiyu Hu

Quanrong Deng

Yangwu Mao

Shenggao Wang
title: Enhanced visible light responsive photocatalytic activity of Bi25FeO40/Bi2Fe4O9 composites and mechanism investigation
venue: Journal of Materials Science: Materials in Electronics
year: 2019

abstract: Polycrystalline Bi2Fe4O9 nanoparticles were successfully prepared by a hydrothermal assisted sol gel method. X ray diffraction (XRD) data, Fourier transform infrared (FTIR) spectra, and Raman spectra reveal that Bi2Fe4O9 nanoparticles has orthorhombic mullite structure without other impurities such as Bi2O3, Fe3O4, BiFeO3, Fe2O3. Scanning electron microscopy (SEM) shows that the synthesized polycrystalline Bi2Fe4O9 particles have regular spherical shape and the average particle size of 50 nm. Optical properties of the Bi2Fe4O9 nanoparticles were studied by UV Vis absorption spectroscopy, and the bandgap energy (Eg) value is found to be 1.75 eV. Magnetic characterization shows that the Bi2Fe4O9 nanoparticles exhibit a paramagnetic behavior at 300 K and undergo an antiferromagnetic transition at 190 K. Ferroelectric hysteresis loops with rounded corners at room temperature at 50 Hz are observed for the Bi2Fe4O9 nanoparticles due to the large electrical leakage. Photocatalytic experiments indicate that the Bi2Fe4O9 nanoparticles exhibit excellent photocatalytic activity and stability in degradation of methylene blue (MB) and methyl red (MR) dyes under visible light irradiation.
author_names: Fu Ma

Hongjian Zhao
title: Optical, Magnetic, Ferroelectric Properties and Photocatalytic Activity of Bi2Fe4O9 Nanoparticles through a Hydrothermal Assisted Sol Gel Method
venue: Russian Journal of Physical Chemistry A
year: 2019

abstract: Polycrystalline Bi2Fe4O9 nanoparticles were successfully prepared by a hydrothermal assisted sol gel method. X ray diffraction (XRD) data, Fourier transform infrared (FTIR) spectra, and Raman spectra reveal that Bi2Fe4O9 nanoparticles has orthorhombic mullite structure without other impurities such as Bi2O3, Fe3O4, BiFeO3, Fe2O3. Scanning electron microscopy (SEM) shows that the synthesized polycrystalline Bi2Fe4O9 particles have regular spherical shape and the average particle size of 50 nm. Optical properties of the Bi2Fe4O9 nanoparticles were studied by UV Vis absorption spectroscopy, and the bandgap energy (Eg) value is found to be 1.75 eV. Magnetic characterization shows that the Bi2Fe4O9 nanoparticles exhibit a paramagnetic behavior at 300 K and undergo an antiferromagnetic transition at 190 K. Ferroelectric hysteresis loops with rounded corners at room temperature at 50 Hz are observed for the Bi2Fe4O9 nanoparticles due to the large electrical leakage. Photocatalytic experiments indicate that the Bi2Fe4O9 nanoparticles exhibit excellent photocatalytic activity and stability in degradation of methylene blue (MB) and methyl red (MR) dyes under visible light irradiation.
title: Optical, Magnetic, Ferroelectric Properties and Photocatalytic Activity of Bi2Fe4O9 Nanoparticles through a Hydrothermal Assisted Sol Gel Method
venue: Russian Journal of Physical Chemistry A
year: 2019

abstract: In this work, ternary all solid state Z scheme g C3N4/carbon nanotubes/Bi2Fe4O9 (g C3N4/CNT/BFO) composites with enhanced photocatalytic activity were prepared by a hydrothermal method. The morphology observation shows that ternary heterojunctions are formed in the g C3N4/CNT/BFO composites. The photocatalytic activity of the samples for the degradation of acid orange 7 was investigated under simulated sunlight irradiation. It was found that the ternary composites exhibit remarkable enhanced photocatalytic activity when compared with bare BFO and g C3N4/BFO composites. The effect of the CNT content on the photocatalytic performance of the ternary composites was investigated. The photocatalytic mechanism of g C3N4/CNT/BFO was proposed according to the photoelectrochemical measurement, photoluminescence, active species trapping experiment and energy band potential analysis. The results reveal that the introduction of CNT as an excellent solid electron mediator into the ternary composites can effectively accelerate the electron migration between BFO and g C3N4. This charge transfer process results in highly efficient separation of photogenerated charges, thus leading to greatly enhanced photocatalytic activity of g C3N4/CNT/BFO composites. Furthermore, the g C3N4/CNT/BFO composites also exhibit highly efficient photo Fenton like catalysis property.
author_names: Lijing Di

Hua Yang

Tao Xian

Xiujuan Chen
title: Construction of Z Scheme g C3N4/CNT/Bi2Fe4O9 Composites with Improved Simulated Sunlight Photocatalytic Activity for the Dye Degradation
venue: Micromachines
year: 2018

abstract: Abstract A series of Bi 2 Fe 4 O 9 /g C 3 N 4 composite photocatalysts are prepared via a facile mixing calcination method. The crystal structures of composites are investigated by X ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT IR) The Field Emission Scanning Electron Microscope (FE SEM) in combination with Energy Dispersive X ray Spectroscopy (EDS) mapping analysis and Transmission Electron Microcopy (TEM) images illustrate the uniform distribution of constituent elements and clear interface between Bi 2 Fe 4 O 9 and g C 3 N 4 component. The visible light driven photocatalytic rates of Rhodamine B over Bi 2 Fe 4 O 9 /g C 3 N 4 composites increase and then decrease with the increase of g C 3 N 4 content. The effects of Bi 2 Fe 4 O 9 /g C 3 N 4 weight ratios on photocatalytic performance are thoroughly discussed. Meanwhile, the active species trapping experiments and the electrochemical impedance spectra as well as the electronic energy band structure estimation analysis demonstrate that the photocatalytic mechanism for Bi 2 Fe 4 O 9 /g C 3 N 4 composites is ascribed to the Z scheme. In addition, the recyclability and stability experiments of the composite are also studied.
author_names: Geming Wang

Shutong Liu

Tiancheng He

Xuan Liu

Quanrong Deng

Yangwu Mao

Shenggao Wang
title: Enhanced visible light driven photocatalytic activities of Bi2Fe4O9/g C3N4 composite photocatalysts
year: 2018