scholarly journals Fabrication and Photocatalytic Properties of Electrospun Fe-Doped TiO2 Nanofibers Using Polyvinyl Pyrrolidone Precursors

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2634
Author(s):  
Kyeong-Han Na ◽  
Bo-Sung Kim ◽  
Han-Sol Yoon ◽  
Tae-Hyeob Song ◽  
Sung-Wook Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Visible Light ◽  
Crystal Phase ◽  
Acid Orange 7 ◽  
Tio2 Nanofibers ◽  
Doped Tio2 ◽  
Acid Orange ◽  
Photodegradation Rate ◽  
Transmission Electron

For the removal of pollutants, a modified TiO2 photocatalyst is attracting attention. Fe-doped TiO2 nanofibers were prepared through a combination of electrospinning and calcination. Morphological characterization of the sample was conducted using field-emission scanning electron and transmission electron microscopy. The crystal structure of each sample was analyzed using high-resolution transmission electron microscopy, selected area electron diffraction, and Fast Fourier Transform imaging. The average diameter of the Fe-doped TiO2 nanofibers was measured to be 161.5 nm and that of the pure TiO2 nanofibers was 181.5 nm. The crystal phase when heat treated at 350 °C was anatase for TiO2 nanofibers and rutile for Fe-doped TiO2 nanofibers. The crystal phase of the TiO2 matrix was easily transitioned to rutile by Fe-doping. The photocatalytic performance of each sample was compared via the photodegradation of methylene blue and acid orange 7 under ultraviolet and visible light irradiation. In the Fe-doped TiO2 nanofibers, photodegradation rates of 38.3% and 27.9% were measured under UV irradiation and visible light, respectively. Although other catalysts were not activated, the photodegradation rate in the Fe-doped TiO2 nanofibers was 9.6% using acid orange 7 and visible light. For improved photocatalytic activity, it is necessary to study the concentration control of the Fe dopant.

Hydrothermal Synthesis of Visible Light Active SnO2-SnS2 Nanocomposite Photocatalyst for the Reduction of Cr(VI) in Water

2013 ◽  
Vol 709 ◽  
pp. 7-10
Author(s):  
Jing Li ◽  
Xi Hua Du ◽  
Wei Min Dai ◽  
Yong Cai Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Sno2 Nanoparticles ◽  
High Photocatalytic Activity ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Light Active ◽  
Composition Structure

A low temperature (130 °C) hydrothermal method was proposed for the synthesis of SnO2-SnS2 nanocomposite. The composition, structure and optical property of the as-synthesized SnO2-SnS2 nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy and UV-vis diffuse reflectance spectra, and its photocatalytic activity was tested by the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation. It was found that the as-synthesized SnO2-SnS2 nanocomposite exhibited high photocatalytic activity in the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation, whereas SnO2 nanoparticles displayed no photocatalytic activity in the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation.

Electron Microscopy of Precious Opal

1968 ◽  
Vol 26 ◽  
pp. 458-459
Author(s):  
Eugene J. Amaral ◽  
Robert C. Rau
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Visible Light ◽  
Amorphous Silica ◽  
Three Dimensional ◽  
Silica Spheres ◽  
Sphere Diameter ◽  
Transmission Electron ◽  
Uniform Diameter ◽  
Precious Opal

Replica and transmission electron microscopy have been used to study the microstructure of precious opal. This mineral is an amorphous silica which is often prized as a gemstone because of its vivid display of iridescent colors when viewed in visible light. For the present study, specimens were examined in fractured, polished, and etched conditions.As shown in the figures, precious opal consists of many tiny silica spheres, of essentially uniform diameter, that have been deposited in an orderly array before silica cementation. Regularly spaced interstitial voids resulting from the ordered packing serve as a three dimensional diffraction grating for visible light, thus giving rise to the characteristic play of colors. The separation of the voids is controlled by sphere diameter, and determines the maximum wavelength of visible light diffracted. Thus specimens consisting of larger spheres diffract higher order colors (longer wavelengths) than specimens consisting of smaller spheres. For example, the specimen shown in Fig. 1 contained spheres of approximately 2700 Å diameter and diffracted all visible colors up through red, while the specimen shown in Fig. 2 contained spheres of approximately 2000 Å diameter and diffracted only blues and greens.

Ion-Exchange Synthesis and Enhanced Visible-Light Photoactivity of Graphene/Hexagonal CuS/Ag2S Nanocomposites

NANO ◽  
2017 ◽  
Vol 12 (01) ◽  
pp. 1750005 ◽  
Author(s):  
Bin Zeng ◽  
Wujun Zeng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Visible Light ◽  
Photocatalytic Performance ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Interfacial Charge ◽  
Visible Light Photocatalytic ◽  
Scanning Electron

Graphene loaded hexagonal CuS/Ag2S nanoplates have been successfully synthesized. Scanning electron microscopy and transmission electron microscopy observations show that hexagonal CuS/Ag2S nanoplates are tightly anchored onto graphene. The experimental results show that these nanocomposites have a highly visible-light photocatalytic performance. The high visible photocatalytic activities can be attributed to direct photoinduced interfacial charge transfer in the hexagonal CuS/Ag2S nanoplates and the further electrons transfer from CuS/Ag2S to graphene.

scholarly journals Preparation of NiS/ZnIn2S4 as a superior photocatalyst for hydrogen evolution under visible light irradiation

2013 ◽  
Vol 4 ◽  
pp. 949-955 ◽  
Author(s):  
Liang Wei ◽  
Yongjuan Chen ◽  
Jialin Zhao ◽  
Zhaohui Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Visible Light ◽  
Hydrogen Evolution ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Co Catalyst ◽  
Photocatalytic Hydrogen Evolution ◽  
X Ray ◽  
Transmission Electron

In this study, NiS/ZnIn2S4 nanocomposites were successfully prepared via a facile two-step hydrothermal process. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Their photocatalytic performance for hydrogen evolution under visible light irradiation was also investigated. It was found that the photocatalytic hydrogen evolution activity over hexagonal ZnIn2S4 can be significantly increased by loading NiS as a co-catalyst. The formation of a good junction between ZnIn2S4 and NiS via the two step hydrothermal processes is beneficial for the directional migration of the photo-excited electrons from ZnIn2S4 to NiS. The highest photocatalytic hydrogen evolution rate (104.7 μmol/h), which is even higher than that over Pt/ZnIn2S4 nanocomposite (77.8 μmol/h), was observed over an optimum NiS loading amount of 0.5 wt %. This work demonstrates a high potential of the developing of environmental friendly, cheap noble-metal-free co-catalyst for semiconductor-based photocatalytic hydrogen evolution.

scholarly journals Bi24Br10+xAgxO31 nanostructure, a new reusable photocatalyst for efficient removal of Acid Blue 92 from model wastewaters under visible light

2019 ◽  
Vol 44 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Mohsen Padervand ◽  
Elham Jalilian
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Visible Light ◽  
Powder Diffraction ◽  
Repeated Treatment ◽  
X Ray ◽  
Transmission Electron ◽  
Acid Blue ◽  
Scanning Electron

Bi24Br10+ xAg xO31 nanosheets were prepared by a facile single-step co-precipitation method in the presence of 1-butyl-3-methylimidazolium bromide ionic liquid as the bromide source and template agent. The products were well characterized by X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray analysis, diffuse reflectance spectroscopy, nitrogen adsorption–desorption isotherms using Brunauer–Emmett–Teller analysis, Fourier transform infrared spectroscopy and transmission electron microscopy. The X-ray powder diffraction pattern confirmed the presence of both Bi24O31Br10 and AgBr crystalline phases in the structure. In addition, the scanning electron microscopy micrographs and transmission electron microscopy image indicated that the sample had sheet-like morphology and the thickness of the sheets was below 100 nm. According to the photocatalytic experiments, the product was exceptionally efficient for the degradation of Acid Blue 92 solutions under visible light. Also, the results of recycling experiments indicated the high capacity of the prepared nanosheets to effect repeated treatment of the wastewater solution, which is of great importance in being introduced as a catalyst in practical applications.

Glycerol-Assisted Hydrolysis Synthesis of BiOCl and Excellent Visible- Light-Driven Photocatalytic Performance

2014 ◽  
Vol 17 (1) ◽  
Author(s):  
Xiaoming Mao ◽  
Min Li ◽  
Yongsheng Jin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Visible Light ◽  
Nitrogen Adsorption ◽  
Diffuse Reflection Spectroscopy ◽  
X Ray Diffraction ◽  
Hydrolysis Method ◽  
Transmission Electron ◽  
Tetragonal Crystal ◽  
Visible Light Driven

AbstractVisible-light-driven bismuth oxychloride (BiOCl) was successfully synthesized by a facile and environmentally friendly glycerol-assisted hydrolysis method at low temperature. The as-prepared BiOCl was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflection spectroscopy (DRS) and nitrogen adsorption. It was found that glycerol played a key role in the formation of BiOCl and the possible growth mechanism was also proposed. The characterization results showed that BiOCl had a tetragonal crystal structure, surface area of 35.30 m

ENHANCED VISIBLE-LIGHT-DRIVEN PHOTOCATALYTIC DEGRADATION PERFORMANCE OF CIP ON BiVO4–Bi2WO6 NANO-HETEROJUNCTION PHOTOCATALYSTS

NANO ◽  
2014 ◽  
Vol 09 (02) ◽  
pp. 1450015 ◽  
Author(s):  
SHAOFANG SUN ◽  
YAFAN WU ◽  
XIAN ZHANG ◽  
ZHONGJIE ZHANG ◽  
YAN YAN ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Light Illumination ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Degradation Ratio ◽  
Band Position ◽  
Visible Light Driven

The removal of CIP from the environment has become a mandatory issue. In our paper, we have realized the visible-light-driven degradation of CIP on the BiVO 4– Bi 2 WO 6 nano-heterojunction photocatalysts. The synthesized photocatalysts were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible (UV-Vis) absorption spectra and photoluminescence (PL) spectra. Compared with the single-phase BiVO 4 and Bi 2 WO 6 counterparts, BiVO 4– Bi 2 WO 6 nano-heterojunction photocatalysts show enhanced photocatalytic degradation activities in visible-light-driven CIP degradation. Particularly, when R( Bi 2 WO 6∕ BiVO 4) = 10 wt .%, the products exhibit the highest CIP degradation ratio in 60 min of 76.8% under visible light illumination. The tentative mechanism of the interface charge transfer (IFCT) effect in the BiVO 4– Bi 2 WO 6 heterojunction structure is also discussed by using the band position calculation.

Preparation of ZnS quantum dot photocatalyst and study on photocatalytic degradation of antibiotics

2019 ◽  
Vol 9 (5) ◽  
pp. 413-418
Author(s):  
Maobin Wei ◽  
Lili Yang ◽  
Yongsheng Yan ◽  
Liang Ni
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Dots ◽  
Quantum Dot ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Photocatalytic Property ◽  
Catalytic Performance ◽  
Structure And Morphology ◽  
Transmission Electron

In this paper, ZnS quantum dot nanomaterials were prepared by means of hydrothermal method and the structure and morphology of the prepared samples were characterized by XRD and transmission electron microscopy (TEM). At the same time, the photocatalytic properties of ZnS quantum dots were studied using antibiotic contaminants ciprofloxacin (CIP) in the environment as the object of degradation. The study showed that the successfully prepared ZnS quantum dot has good photocatalytic property under UV irradiation, it can effectively degrade the antibiotic contaminant ciprofloxacin in the environment, but its catalytic performance under visible light is not high and its degradation efficiency is only 45.75%.

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