scholarly journals Photocatalytic Reduction Activity of 001  TiO2 Codoped with F and Fe under Visible Light for Bromate Removal

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yan Zhang ◽  
Lingdan Li ◽  
Hongyuan Liu
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Reduction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Reduction Activity ◽  
Transmission Electron ◽  
Carcinogenic Potential ◽  
Microstructure Morphology ◽  
Electron Paramagnetic

The presence of bromate in water is a well-known problem because of its toxic effects on human health, particularly its carcinogenic potential. Photocatalytic reduction is an attractive process for bromate removal. F- and Fe-codoped TiO2 (F-Fe-TiO2) with a {001} facet was successfully prepared, and its bromate-removal activity under visible light was examined. The microstructure, morphology, and chemical state of the doping elements and the optical property of the photocatalysts were examined using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), photoluminescence spectroscopy (PLS), and UV-Vis diffuse reflectance spectra (DRS). The results indicate that the optical properties of F-Fe-TiO2 with the {001} facet and cuboid morphology were obviously improved and its photocatalytic activity was significantly enhanced. The bromate solution of 100 μg/L was thoroughly removed with 0.5 g/L dosage of 1.0% F- and 0.08% Fe-codoped TiO2 composite within 1 hour under visible light.

Jellyfish-like few-layer graphene nanoflakes: high paramagnetic response alongside increased interlayer interaction

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Alexander Ulyanov ◽  
Dmitrii Stolbov ◽  
Serguei Savilov
Keyword(s):  
Photoelectron Spectroscopy ◽  
High Sensitivity ◽  
Paramagnetic Centers ◽  
Interlayer Interaction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Graphene Nanoflakes ◽  
Few Layer Graphene ◽  
Electron Paramagnetic ◽  
Hydrocarbon Pyrolysis

Abstract Jellyfish-like graphene nanoflakes (GNF), prepared by hydrocarbon pyrolysis, are studied with electron paramagnetic resonance (EPR) method. The results are supported by X-ray photoelectron spectroscopy (XPS) data. Oxidized (GNFox) and N-doped oxidized (N-GNFox) flakes exhibit an extremely high EPR response associated with a large interlayer interaction which is caused by the structure of nanoflakes and layer edges reached by oxygen. The GNFox and N-GNFox provide the localized and mobile paramagnetic centers which are silent in the pristine (GNF p ) and N-doped (N-GNF) samples. The change in the relative intensity of the line corresponding to delocalized electrons is parallel with the number of radicals in the quaternary N-group. The environment of localized and mobile electrons is different. The results can be important in GNF synthesis and for explanation of their features in applications, especially, in devices with high sensitivity to weak electromagnetic field.

FeYO3@rGO nanocomposites: Synthesis, characterization and application in photooxidative degradation of atrazine under visible light

2021 ◽  
Vol 11 (5) ◽  
pp. 706-716
Author(s):  
Nada D. Al-Khthami ◽  
Tariq Altalhi ◽  
Mohammed Alsawat ◽  
Mohamed S. Amin ◽  
Yousef G. Alghamdi ◽  
...  
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Structural Surface ◽  
Adsorption Desorption

Different organic pollutants have been remediated photo catalytically by applying perovskite photocatalysts. Atrazine (ATR) is a pesticide commonly detected as a pollutant in drinking, surface and ground water. Herein, FeYO3@rGO heterojunction was synthesized and applied for photooxidation decomposition of ATR. First, FeYO 3nanoparticles (NPs) were prepared via routine sol-gel. After that, FeYO3 NPs were successfully incorporated with different percentages (5, 10, 15 and 20 wt.%) of reduced graphene oxide (rGO) in the synthesis of novel FeYO3@rGO photocatalyst. Morphological, structural, surface, optoelectrical and optical characteristics of constructed materials were identified via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), adsorption/desorption isotherms, diffusive reflectance (DR) spectra, and photoluminescence response (PL). Furthermore, photocatalytic achievement of the constructed materials was evaluated via photooxidative degradation of ATR. Various investigations affirmed the usefulness of rGO incorporation on the advancement of formed photocatalysts. Actually, novel nanocomposite containing rGO (15 wt.%) possessed diminished bandgap energy, as well as magnified visible light absorption. Furthermore, such nanocomposite presented exceptional photocatalytic achievement when exposed to visible light as ATR was perfectly photooxidized over finite amount (1.6 g · L-1) from the optimized photocatalyst when illuminated for 30 min. The advanced photocatalytic performance of constructed heterojunctions could be accredited mainly to depressed recombination amid induced charges. The constructed FeYO3@rGO nanocomposite is labelled as efficient photocatalyst for remediation of herbicides from aquatic environments.

Fabrication, characterization and magnetic properties of Na-doped ZnO nanorods

2016 ◽  
Vol 09 (03) ◽  
pp. 1650039 ◽  
Author(s):  
Jingyuan Piao ◽  
Li-Ting Tseng ◽  
Kiyonori Suzuki ◽  
Jiabao Yi
Keyword(s):  
Magnetic Measurements ◽  
Zno Nanorods ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Shallow Donors ◽  
Na Doping ◽  
Transmission Electron ◽  
Doped Zno ◽  
Electron Paramagnetic

Na-doped ZnO nanorods have been fabricated through a hydrothermal method. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses indicate that the d spacing of ZnO increases with increasing doping concentration, suggesting the effective incorporation of dopant Na in the samples. Electron paramagnetic resonance (EPR) measurements indicate that there are shallow donors in pure ZnO samples and the shallow donors are strongly prohibited by Na doping. In addition, the resonance at g = 2.005 suggests the formation of Zn vacancies. Magnetic measurements indicate that pure ZnO is paramagnetic and Na doping leads to ferromagnetism at room temperature. Moreover, 0.5% Na-doped ZnO nanorods exhibits the largest saturation magnetization.

scholarly journals Preparation and Characterization of Defective TiO2. The Effect of the Reaction Environment on Titanium Vacancies Formation

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2763
Author(s):  
Zuzanna Bielan ◽  
Szymon Dudziak ◽  
Agnieszka Sulowska ◽  
Daniel Pelczarski ◽  
Jacek Ryl ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Reaction ◽  
High Photocatalytic Activity ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Light Activity ◽  
Cheap Alternative

Among various methods of improving visible light activity of titanium(IV) oxide, the formation of defects and vacancies (both oxygen and titanium) in the crystal structure of TiO2 is an easy and relatively cheap alternative to improve the photocatalytic activity. In the presented work, visible light active defective TiO2 was obtained by the hydrothermal reaction in the presence of three different oxidizing agents: HIO3, H2O2, and HNO3. Further study on the effect of used oxidant and calcination temperature on the physicochemical and photocatalytic properties of defective TiO2 was performed. Obtained nanostructures were characterized by X-ray diffractometry (XRD), specific surface area (BET) measurements, UV-Vis diffuse reflectance spectroscopy (DR-UV/Vis), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR) spectroscopy. Degradation of phenol as a model pollutant was measured in the range of UV-Vis and Vis irradiation, demonstrating a significant increase of photocatalytic activity of defective TiO2 samples above 420 nm, comparing to non-defected TiO2. Correlation of EPR, UV-Vis, PL, and photodegradation results revealed that the optimum concentration of HIO3 to achieve high photocatalytic activity was in the range of 20–50 mol%. Above that dosage, titanium vacancies amount is too high, and the obtained materials’ photoactivity was significantly decreased. Studies on the photocatalytic mechanism using defective TiO2 have also shown that •O2− radical is mainly responsible for pollutant degradation.

Sequestered carbon on clay mineral probed by electron paramagnetic resonance and X-ray photoelectron spectroscopy

2006 ◽  
Vol 295 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Kátia Cylene Lombardi ◽  
Antonio Salvio Mangrich ◽  
Fernando Wypych ◽  
Ubirajara Pereira Rodrigues-Filho ◽  
José L. Guimarães ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Clay Mineral ◽  
Photoelectron Spectroscopy ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Electron Paramagnetic

One-Pot Hydrothermal Synthesis of Sulfur-Doped SnO2 Nanoparticles and their Enhanced Photocatalytic Properties

NANO ◽  
2016 ◽  
Vol 11 (03) ◽  
pp. 1650035 ◽  
Author(s):  
Lin Ma ◽  
Limei Xu ◽  
Xuyao Xu ◽  
Xiaoping Zhou ◽  
Lingling Zhang
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Sno2 Nanoparticles ◽  
Light Response ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Light Region ◽  
Vis Spectroscopy

Sulfur-doped SnO2 nanoparticles with ultrafine sizes have been successfully prepared by a one-pot hydrothermal method. The obtained samples are characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM), thermogravimetric (TG), analyzer UV-Vis spectroscopy, photoluminescence (PL) and electrochemical impedance spectroscopy (EIS). The experimental results indicate that the doping level of sulfur element as well as the bandgaps of SnO2 can be controlled to a certain extent by varying the amount of L-cysteine (L-cys). When evaluated as photocatalysts in the degradation of rhodamine B (RhB) and reduction of Cr(VI) under visible light region, the resultant sulfur-doped SnO2 nanoparticles demonstrate obviously enhanced photocatalytic activities due to the markedly improved visible light response and effective separation of the photo-generated electron–hole pairs.

scholarly journals Correction: Synchrotron-based X-ray spectromicroscopy and electron paramagnetic resonance spectroscopy to investigate the redox properties of lead chromate pigments under the effect of visible light

2015 ◽  
Vol 30 (9) ◽  
pp. 2024-2024 ◽  
Author(s):  
Letizia Monico ◽  
Koen Janssens ◽  
Marine Cotte ◽  
Aldo Romani ◽  
Lorenzo Sorace ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Visible Light ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Redox Properties ◽  
Resonance Spectroscopy ◽  
Lead Chromate ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Electron Paramagnetic

Correction for ‘Synchrotron-based X-ray spectromicroscopy and electron paramagnetic resonance spectroscopy to investigate the redox properties of lead chromate pigments under the effect of visible light’ by Letizia Monico et al., J. Anal. At. Spectrom., 2015, 30, 1500–1510.

A COST-EFFECTIVE MAGNETIC PHOTOCATALYST PALYGORSKITE–TiO2–FexOy WITH EXCELLENT PERFORMANCE FOR DYE PHOTODEGRADATION UNDER VISIBLE LIGHT

NANO ◽  
2014 ◽  
Vol 09 (06) ◽  
pp. 1450063
Author(s):  
JIAHUI ZHANG ◽  
LILI ZHANG ◽  
JIN HUANG ◽  
SHOUYONG ZHOU ◽  
HAIQUN CHEN ◽  
...  
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Cost Effective ◽  
Magnetic Photocatalyst ◽  
X Ray ◽  
Transmission Electron ◽  
Light Region ◽  
Reaction Solution ◽  
Excellent Photocatalytic Activity ◽  
Average Size

Palygorskite (denoted as Pal) was used as an economical carrier of hybrid photocatalyst TiO 2– Fe x O yvia an in situ depositing technique (marked as Pal– TiO 2– Fe x O y). The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), brunner-emmet-teller (BET) measurements, X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflectance spectra measurements. Results showed that TiO 2– Fe x O y composite particles with average size of about 10 nm were loaded onto the Pal fibers' surface. Fe x O y acted not only as magnetic source but also took part in the formation of TiO 2– Fe x O y heterojunction structure, which resulted in the obvious absorption in visible light region for the obtained Pal– TiO 2– Fe x O y composite photocatalyst. The obtained Pal– TiO 2– Fe x O y shows excellent photocatalytic activity toward photodegradation of Methyl orange (MO) under visible light irradiation and the degradation ratio reached 94% within 180 min. Moreover, Pal– TiO 2– Fe x O y could be readily recovered from the reaction solution by the magnet. Possible mechanism for the enhancement was also proposed.

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