scholarly journals Synthesis of Spherical Bi2WO6Nanoparticles by a Hydrothermal Route and Their Photocatalytic Properties

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
B. Wang ◽  
H. Yang ◽  
T. Xian ◽  
L. J. Di ◽  
R. S. Li ◽  
...  

Spherical Bi2WO6nanoparticles were synthesized by a hydrothermal route. SEM observation shows that the size of the particles ranges from 60 to 120 nm and the average particle size is ~85 nm. TEM investigation shows that the particles are made up of subgrains with size of 5–10 nm. The bandgap energy of the particles is measured to be 2.93 eV by ultraviolet-visible diffuse reflectance spectroscopy. RhB was chosen as the target pollutant to evaluate the photocatalytic activity of the particles under irradiation of simulated sunlight, revealing that they exhibit an obvious photocatalytic activity. The effects of ethanol, KI, and BQ on the photocatalytic efficiency of Bi2WO6particles towards the RhB degradation were investigated. It is observed that ethanol has no effect on the photocatalytic degradation of RhB, whereas KI and BQ exhibit a substantial suppression of RhB degradation. No hydroxyl (•OH) is found, by the photoluminescence technique using terephthalic acid as a probe molecule, to be produced over the irradiated Bi2WO6particles. Based on the experimental results, photoexcited hole (h+) and superoxide (•O2-) are suggested to be the two main active species responsible for the dye degradation, while •OH plays a negligible role in the photocatalysis.

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 613 ◽  
Author(s):  
Lijing Di ◽  
Hua Yang ◽  
Tao Xian ◽  
Xiujuan Chen

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.


2012 ◽  
Vol 178-181 ◽  
pp. 535-538
Author(s):  
Jing Jiao Zhang ◽  
Pei Song Tang

The single phase BiTaO4was synthesized using Ta2O5and Bi(NO3)3as main raw materials by precipitation process. The products were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). The results show that BiTaO4was triclinic crystal with average particle size 100nm, and a band gap of about 2.77 eV. The photocatalytic experiment of BiTaO4shows the good photocatalytic activity for the decomposition of methylene blue under visible-light irradiation.


2021 ◽  
Vol 13 (9) ◽  
pp. 1756-1763
Author(s):  
Hamdah S. Alanazi ◽  
Hanan Alotaibi ◽  
Hamza S. Al-Shehri ◽  
Fahad A. Alharthi

In this presented work, ziziphus spina-christi leaves extract assisted green synthesise approach was used to prepare the NiO nanoparticle for UV light driven photocatalytic methylene blue (MB) dye degradation. Various analytical characterizations were used to understand the crystalline, structural, optical and morphological nature of the prepared nanoparticle. The prepared NiO nanoparticle have wide bandgap of 3.35 eV with average particle size of around 10–15 nm in range. Various environmental conditions and elemental trapping experiments were conducted to understand the factors affecting the MB degradation and main active species for the redox reaction. Hence, we hope that this green synthesise NiO would pave a new way for photocatalytic preparation and their environmental remediation application.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sadia Ata ◽  
Ifra Shaheen ◽  
Farzana Majid ◽  
Ismat Bibi ◽  
Ijaz-ul-Mohsin ◽  
...  

Abstract Manganese ferrite (MnFe2O4) was prepared via hydrothermal route and characterized by advanced techniques. The photocatalytic activity (PCA) was evaluated by degrading methylene blue (MB) dye under UV irradiation. The effect of process variables such as catalyst dose, UV exposure time and pH was studied for maximum degradation of dye at optimum conditions. The MnFe2O4 showed face centered cubic structure and average particle size of 23.98 nm. The lattice constant, lattice strain, ionic radii (rA & rB), bonding angles and hoping lengths of MnFe2O4 were recorded to be 0.8467 nm, 0.08, 1.66, 0.766, 1.833 and 2.116 Å, respectively. The MnFe2O4 showed promising PCA and at optimum conditions of process variable, up to 99% MB dye degradation was achieved. The PCA was found dependent to catalyst dose, UV exposure time and pH. Results revealed that the hydrothermal rout is feasible route for the preparation of MnFe2O4 ferrite in nano size and the PCA revealed the potential application of MnFe2O4 ferrite to degrade dye in textile wastewater.


2016 ◽  
Vol 15 (05n06) ◽  
pp. 1660002 ◽  
Author(s):  
V. Kavitha ◽  
P. S. Ramesh ◽  
D. Geetha

Copper doped Titanium dioxide TiO2 nanoparticles were synthesized by sol–gel method using titanium tetraisopropoxide and copper sulfate as precursors. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), UV-Visible spectroscopy (UV-Vis), Photoluminesce spectroscopy (PL) and atomic force microscopy (AFM). XRD analysis confirms the formation of anatase titanium dioxide and average particle size was 35[Formula: see text]nm. Cu– TiO2 exhibits a shift in the absorption edge toward visible spectrum. The rate of recombination and transfer behavior of the photoexcited electron–hole pairs in the semiconductors was recorded by photoluminescence. From SEM spherical shaped nanoparticles was observed. Comparing with pure TiO2 nanoparticles, Cu doped TiO2 photocatalyst exhibited enhanced photocatalytic activity under natural sunlight irradiation in the decomposition of rhodamine B aqueous solution. The maximum 97% of degradation efficiency of Rhodamine B was observed at 0.6% Cu–TiO2 within 180[Formula: see text]min. The photocatalytic efficiency of Rhodamine B of Cu doped TiO2 nanoparticle was higher than the pure TiO2, which could be attributed to the small crystallinity intense light absorption in Sunlight and narrow bandgap energy of Copper.


2011 ◽  
Vol 335-336 ◽  
pp. 1385-1390 ◽  
Author(s):  
Shuo Wiei Zhao ◽  
Hui Xu ◽  
Hua Ming Li ◽  
Yuan Guo Xu

In order to improve the photocatalytic activity, Co was successfully loaded into Ag3VO4 by using impregnation process. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS) and diffuse reflectance spectroscopy (DRS). The XRD and SEM–EDS analyses revealed that Co ion was dispersed on Ag3VO4. The DRS results indicated that the absorption edge of the Co–Ag3VO4 catalyst shifted to longer wavelength. The enhanced photocatalytic activity of Co–Ag3VO4 for Methylene Blue(MB) dye degradation under visible light irradiation was due to its wider absorption edge and higher separation rate of photo-generated electron and holes. In the experimental conditions, it is demonstrated that the MB was effectively degraded by more than 95% within 40 min when the Co–Ag3VO4 catalyst was calcined at 300°C with 1 wt.% Co content.


2014 ◽  
Vol 809-810 ◽  
pp. 890-894
Author(s):  
Dan Li ◽  
Lian Wei Shan ◽  
Gui Lin Wang ◽  
Li Min Dong ◽  
Wei Li ◽  
...  

Boron-BiVO4 samples were synthesized by sol-gel method. They were characterized by UV-vis diffuse reflectance spectroscopy, X-ray diffraction. Photocatalytic activity of the obtained BiVO4 samples was investigated through degrading methylene blue (MB). The results reveal that boron-BiVO4 catalysts have monoclinic scheelite structure. The BiVO4 and Co-BiVO4 photocatalysts were responsive to visible light. Co-BiVO4 photocatalyst showed higher photocatalytic activity than pure BiVO4, resulting in the significantly improved efficiency of degradation of MB.


2021 ◽  
Author(s):  
Mahesh Gaidhane ◽  
Deepak Taikar ◽  
Pravin Gaidhane ◽  
Kalpana Nagde

Abstract Nanocrystalline α-Fe2O3 is synthesized by sol-gel technique. The prepared nanomaterial was characterized by X-ray diffraction (XRD), SEM, TEM, Fourier Transform Infrared (FTIR) spectroscopy, Vibrating Sample Magnetometry (VSM) and photoluminescence (PL) techniques. X-ray powder diffraction analysis confirmed the formation of α-Fe2O3. Electron microscopy showed spherical morphologies with an average particle size of 30-40 nm. The magnetic property of the prepared material was studied by VSM at room temperature. VSM study shows superparamagnetic nature of the synthesized nanoparticles. Photoluminescence (PL) emission spectra show intense broad emission band centered at 570 nm with 393 nm excitation indicating its usefulness for w-LED application. The CIE-chromaticity color coordinates of prepared material were calculated. The photocatalytic activity of the α-Fe2O3 nanoparticles was analyzed and the nanopowder exhibited good photocatalytic activity for the removal AO7 from its aqueous solution.


2021 ◽  
Vol 15 (2) ◽  
pp. 179-183
Author(s):  
Huaxing Meng ◽  
Zhiwu Chen ◽  
Zhenya Lu ◽  
Xin Wang ◽  
Xiaoyi Fu

Monodispersed tetragonal barium titanate (BaTiO3) nanopowders were synthesized by a convenient hydrothermal route at a low temperature of 200?C in only 24 h. The key point of this method is to promote the generation of ultrafine titanium hydroxide precipitation precursors with the help of absolute ethyl alcohol and ammonia solution during the hydrolysis of Ti(OC4H9)4. The results of X-ray diffraction and Raman spectra show that the as-prepared BaTiO3 nanopowders possess tetragonal-dominant structure. The synthesized tetragonal BaTiO3 nanopowders exhibit relatively uniform size and good dispersity, with the average particle size of 96.1 nm and a tetragonality of 1.0073, which enable broad application prospects in the field of multilayer ceramic capacitors.


2021 ◽  
Vol 22 (48) ◽  
Author(s):  
Tran Thi Bich Quyen ◽  
Ngo Nguyen Tra My ◽  
Do Thi Thuy Ngan ◽  
Duy Toan Pham ◽  
Doan Van Hong Thien

For the first time, cuprous oxide nanocubes (Cu2O NCBs) were successfully combined with chitosan nanoparticles (CS NPs) to generate Cu2O NCBs/CS NPs composites material with highly optical property and photocatalytic activity using a simple and eco-friendly synthetic approach at room temperature for 30 min. The synthesized Cu2O NCBs NPs/CS NPs were determined characterizations by Ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), X – ray Diffraction (XRD),  Transmission Electron Microscope (TEM) and Energy-dispersive X-ray spectroscopy (EDX). Results show that the Cu2O NCBs/CS NPs composites have an average particle size of ~3-5 nm; in which, Cu2O has the form of nanocubes (Cu2O NCBs) with size ~3-4 nm and chitosan nanoparticles with spherical shape (CS NPs) with size ~4-5 nm. In addition, the percent (%) composition of elements present in Cu2O NCBs/CS NPs composites material have been obtained respective: Cu (23.99%), O (38.18%), and C (33.61%). Moreover, Cu2O NCBs/CS NPs composites material was also investigated for photocatalytic activity applied in p-nitrophenol degradation. The obtained results showed that the catalytic capability of Cu2O NCBs/CS NPs for p-nitrophenol reduction reached the highest efficiency >55% in the treatment time of 25 min, and this efficiency was higher than that result of using ZnO@chitosan nanoparticles (ZnO@CS NPs) catalyst under the same conditions for comparison.


Sign in / Sign up

Export Citation Format

Share Document