scholarly journals Conversion of Organic Matter in Coal by Photocatalytic Oxidation with H2O2 over SFC/TiO2 in Isolated Oxygen System

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Heng-Shen Xie ◽  
Zhi-Min Zong ◽  
Yu-Gao Wang ◽  
Pei-Zhi Zhao ◽  
Shi-Hua Zhang ◽  
...  
Keyword(s):  
Photocatalytic Oxidation ◽  
Bituminous Coal ◽  
Uv Light ◽  
Structural Characteristics ◽  
Gas Chromatograph ◽  
Hydrogen Atoms ◽  
Alkyl Radicals ◽  
Oxygen System ◽  
Branched Chain ◽  
Oxidation Effect

Shenfu bituminous coal (SFBC), Geting coal (GTC), Shengli lignite (SLL), and Holingola coal (HLGLC) were oxidized by UV light radiation with aqueous H2O2 over SFC/TiO2 in a closed suspension system (CSS) to understand structural characteristics of 4 typical Chinese coals. Raw and oxidized coals were dried and extracted with acetone thoroughly to ensure residue extraction. Meanwhile, the extracts were analyzed using a gas chromatograph/mass spectrometer. The results show that organic matters (OMs) in coals can be converted into a large number of oxygen-containing organic compounds (OCOCs), mainly containing ketones, esters, alcohols, etc. Oxidizing species such as hydroxyls, hydroperoxyl, and alkyl radicals are excited by light irradiation and substitute for hydrogen atoms of methyls and methylenes of acenes or branched-chain alkanes in coals. Acetic acid and acetaldehyde can be formed and dissolved in aqueous solution in the oxidation reaction. The yields can be improved with the enhancement of the oxidation effect.

Photocatalytic Oxidation of Shenfu Bituminous Coal and Xilinhaote Lignite with H2O2 over TiO2

2011 ◽  
Vol 233-235 ◽  
pp. 1684-1689 ◽  
Author(s):  
Heng Shen Xie ◽  
Zhi Min Zong ◽  
Qing Wei ◽  
Pei Zhi Zhao ◽  
Jian Jun Zhao ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Titanium Dioxide ◽  
Catalytic Oxidation ◽  
Photocatalytic Oxidation ◽  
Bituminous Coal ◽  
Straight Chain ◽  
Photo Catalytic Oxidation ◽  
Alkyl Side Chains ◽  
Lignite Coal ◽  
Oxidation Effect

Shenfu bituminous coal (SFBC) and Xilinhaote lignite (XL) were subject to photo-catalytic oxidation with hydrogen peroxide over titanium dioxide. The reaction mixtures were extracted with acetone exhaustively. The extracts were analyzed with FTIR and GC/MS. The results show that coals be oxidized selectively and degraded partially. Compared with the bituminite coal, the oxidation effect of the lignite coal with active hydrogens is more obvious. The alkyl side chains of the macromolecules, particularly, chains of methyl, methylene and aromatic, are the most vulnerable in relation to other compounds in coals. Moreover, the increasing of straight-chain alkanes and the decreasing of condensed nucleus in SFBC and XL through oxidation suggest that the oxidation is an effective method of coal utilization with no difficultly, also be friendly towards the environment after treated as well as in the process of the treatment.

scholarly journals Study of Iron Gall Inks, Ingredients and Paper Composition Using Non-Destructive Techniques

Heritage ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 2691-2703 ◽  
Author(s):  
Victoria Corregidor ◽  
Rita Viegas ◽  
Luís M. Ferreira ◽  
Luís C. Alves
Keyword(s):  
Structural Information ◽  
Uv Light ◽  
Raw Materials ◽  
Structural Characteristics ◽  
Crystallinity Index ◽  
X Ray ◽  
Paper Degradation ◽  
Iron Gall ◽  
Non Destructive ◽  
Non Destructive Techniques

Old manuscripts are among the most important elements of the cultural and historical heritage of ancient knowledge. Unfortunately, many of them suffer from degradation, mostly those written with iron gall inks. In the present work, a study using non-destructive techniques was designed with the aim of analyzing the elemental composition and structural characteristics of iron gall inks, reproduced in laboratory, paper and their interaction when the ink is deposited on paper, inducing the paper degradation. Proton induced X-ray emission, X-ray diffraction and Fourier-transform infrared spectroscopy provided the elemental and structural information, and photography under infrared (IR) and ultraviolet (UV) light allowed the differentiation between manufactured inks. Results show that the first step of inked paper deterioration is due to acid-hydrolysis of the cellulose and the presence of reactive Fe(II) species by reducing the crystallinity index of the paper, which is affected depending on the ink recipe and the starting raw materials. These results will be useful to future studies on ancient documents written with iron gall inks, which suffer deterioration due to ink corrosion, and to differentiate between the different paper degradation mechanisms.

Photocatalytic Treatment of Wastewater From 5–Fluorouracil Manufacturing

1996 ◽  
Vol 118 (1) ◽  
pp. 2-8 ◽  
Author(s):  
M. Anheden ◽  
D. Y. Goswami ◽  
G. Svedberg
Keyword(s):  
Hydrogen Peroxide ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Substantial Reduction ◽  
Reduction Rate ◽  
Reaction Rates ◽  
Batch Experiments ◽  
Cod Reduction ◽  
Potential Use ◽  
Percent Decrease

This paper presents some of the experimental results from a study conducted to demonstrate the potential use of photocatalytic oxidation for decolorization and COD reduction of wastewater from 5–fluorouracil manufacturing. A series of batch experiments, were carried out using diluted solutions of the wastewater with 0.1 percent w/v TiO2. Low pressure mercury lamps were used to simulate the UV part of sunlight. The experiments showed that a complete decolorization and a substantial reduction of COD was achieved within 20 hours with a 20 percent solution. During the reaction period, the pH was noted to decrease considerably, indicating formation of acids. Adding hydrogen peroxide to the solution was found to significantly increase the reaction rates. Adding 2400 ppm of H2O2 gave an 80 percent decrease in color in one hour and a 70-80 percent decrease in COD in 20 hours. The influence of UV-light intensity was also examined. This experiment showed that with a UV-intensity of 15 W/m2, i.e., a cloudy day, the decolorization rate was still considerable, while the COD reduction rate was very low.

scholarly journals Combining the Photocatalysis and Absorption Properties of Core-Shell Cu-BTC@TiO2 Microspheres: Highly Efficient Desulfurization of Thiophenic Compounds from Fuel

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2209 ◽  
Author(s):  
Jing Liu ◽  
Xiao-Min Li ◽  
Jing He ◽  
Lu-Ying Wang ◽  
Jian-Du Lei
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Sulfur Removal ◽  
Oxidation Products ◽  
Core Shell ◽  
Adsorptive Desulfurization ◽  
X Ray ◽  
Tio2 Microspheres

A core-shell Cu-benzene-1,3,5-tricarboxylic acid (Cu-BTC)@TiO2 was successfully synthesized for photocatalysis-assisted adsorptive desulfurization to improve adsorptive desulfurization (ADS) performance. Under ultraviolet (UV) light irradiation, the TiO2 shell on the surface of Cu-BTC achieved photocatalytic oxidation of thiophenic S-compounds, and the Cu-BTC core adsorbed the oxidation products (sulfoxides and sulfones). The photocatalyst and adsorbent were combined using a distinct core-shell structure. The morphology and structure of the fabricated Cu-BTC@TiO2 microspheres were verified by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive x-ray spectroscopy, X-ray powder diffraction, nitrogen adsorption-desorption and X-ray photoelectron spectroscopy analyses. A potential formation mechanism of Cu-BTC@TiO2 is proposed based on complementary experiments. The sulfur removal efficiency of the microspheres was evaluated by selective adsorption of benzothiophene (BT) and dibenzothiophene (DBT) from a model fuel with a sulfur concentration of 1000 ppmw. Within a reaction time of 20 min, the BT and DBT conversion reached 86% and 95%, respectively, and achieved ADS capacities of 63.76 and 59.39 mg/g, respectively. The BT conversion and DBT conversion obtained using Cu-BTC@TiO2 was 6.5 and 4.6 times higher, respectively, than that obtained using Cu-BTC. A desulfurization mechanism was proposed, the interaction between thiophenic sulfur compounds and Cu-BTC@TiO2 microspheres was discussed, and the kinetic behavior was analyzed.

scholarly journals Investigation on Parameters Affecting the Effectiveness of Photocatalytic Functional Coatings to Degrade NO: TiO2 Amount on Surface, Illumination, and Substrate Roughness

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
J. Hot ◽  
J. Topalov ◽  
E. Ringot ◽  
A. Bertron
Keyword(s):  
Visible Light ◽  
Dry Matter ◽  
Photocatalytic Oxidation ◽  
Building Materials ◽  
Uv Light ◽  
Matter Content ◽  
Photochemical Oxidation ◽  
Dry Matter Content ◽  
Functional Coatings ◽  
Substrate Roughness

This paper deals with the degradation of NO by photocatalytic oxidation using TiO2-based coatings. Tests are conducted at a laboratory scale through an experimental setup inspired from ISO 22197-1 standard. Various parameters are explored to evaluate their influence on photocatalysis efficiency: TiO2 dry matter content applied to the surface, nature of the substrate, and illumination conditions (UV and visible light). This article points out the different behaviors between three kinds of substrates which are common building materials: normalized mortar, denser mortar, and commercial wood. The illumination conditions are of great importance in the photocatalytic process with experiments under UV light showing the best results. However, a significant decrease in NO concentration under visible light is also observed provided that the TiO2 dry matter content on the surface is high enough. The nature of the substrate plays an important role in the photocatalytic activity with rougher substrates being more efficient to degrade NO. However, limiting the roughness of the substrate seems to be of utmost interest to obtain the highest exposed surface area and thus the optimal photocatalytic efficiency. A higher roughness promotes the surface contact between TiO2 and NO but does not necessarily increase the photochemical oxidation.

Study on the Photo-Electro-Catalytic Oxidation of Methane

2013 ◽  
Vol 864-867 ◽  
pp. 1421-1426
Author(s):  
Wen Yan Wu ◽  
Luo Chun Wang ◽  
Zhen Zhou ◽  
Ke Jia Liu ◽  
Xiao Hua Li ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Ambient Pressure ◽  
Kinetic Constant ◽  
Illumination Time ◽  
Oxidation Of Methane ◽  
Conversion Of Methane ◽  
Intermittent Illumination ◽  
Electro Catalytic Oxidation

Emission control of methane from landfills has received considerable attentions in recent years. Photo-electro-catalytic oxidation of methane was carried out at the mode of continuous electrolysis and intermittent illumination with TiO2-coated titanium mesh plate as pholocatalyst and electrode in combination with ionic liquid as electrolyte under UV light irradiation. The result showed that the rapid conversion of methane was achieved under ambient pressure and temperature through photocatalytic oxidation combining with electrolysis. Under the mode of intermittent illumination (on:off = 10 min : 10 min) and continuous electrolysis (II-CE), the highest oxidation rate of methane (280 mg/(m3min)) was obtained. Under fixed off time and total illumination time, the oxidation quantity of methane linearly increased with the intermittent frequency. Photo-electro-catalytic oxidation of methane can be described by the first-order kinetics, and the apparent kinetic constant increased with the intermittent frequency.

Structural characteristics and UV-light enhanced gas sensitivity of La-doped ZnO nanoparticles

2007 ◽  
Vol 141 (1-2) ◽  
pp. 43-48 ◽  
Author(s):  
Chunqiao Ge ◽  
Changsheng Xie ◽  
Mulin Hu ◽  
Yanghai Gui ◽  
Zikui Bai ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Uv Light ◽  
Structural Characteristics ◽  
Gas Sensitivity ◽  
Doped Zno ◽  
La Doped

Photocatalytic Oxidation of Nitrogen Dioxide with TiO2 Thin Films under Continuous UV-Light Illumination

2008 ◽  
Vol 112 (28) ◽  
pp. 10502-10508 ◽  
Author(s):  
Yoshihisa Ohko ◽  
Yuri Nakamura ◽  
Akari Fukuda ◽  
Sadao Matsuzawa ◽  
Koji Takeuchi
Keyword(s):  
Thin Films ◽  
Nitrogen Dioxide ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Light Illumination ◽  
Tio2 Thin Films

Preparation and enhanced photocatalytic oxidation activity of surface-modified CdS nanoparticles with high photostability

1999 ◽  
Vol 14 (5) ◽  
pp. 2092-2095 ◽  
Author(s):  
M. Y. Han ◽  
W. Huang ◽  
C. H. Quek ◽  
L. M. Gan ◽  
C. H. Chew ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Modification ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Cds Nanoparticles ◽  
Oxidation Activity ◽  
Chemical Surface ◽  
Photo Oxidation ◽  
Chemical Surface Modification ◽  
Surface Modified

Highly photostable CdS nanoparticles modified with an alkyl group were prepared by an improved microemulsion technique using hexanethiol as cosurfactant. The surface-modified CdS nanoparticles catalyzed the photo-oxidation of 4-chlorophenol via continuously bubbling oxygen under uv light. The photocatalytic oxidation activity of the CdS nanoparticles was enhanced due to the formation of their compact CdS cores with strong chemical surface modification by heat treatment.

Improvement of TiO2/LDPE Composite Films for Photocatalytic Oxidation of Acetone

2014 ◽  
Vol 931-932 ◽  
pp. 235-240 ◽  
Author(s):  
Kowit Suwannahong ◽  
Sanya Sirivithayapakorn ◽  
Pongsak Noophan ◽  
Wipada Sanongraj
Keyword(s):  
Composite Film ◽  
Photocatalytic Oxidation ◽  
Fourier Transforms ◽  
Uv Light ◽  
Composite Films ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Closed Chamber ◽  
Acetone Concentration ◽  
Ftir Spectrometer

Titanium dioxide with coupling agent (ETES) was applied as a photocatalyst for a synthesis of the TiO2/LDPE composite film. The physical properties of TiO2/LDPE composite film were analyzed by a Scanning Electron Microscope (SEM). TiO2 particles were impregnated into the polymer matrix film as a LDPE composite film. The results from the X-ray Diffraction (XRD) technique revealed that the structure of TiO2/LDPE composite film were anatase crystalline. The chemical structure of the TiO2/ LDPE composite films were analyzed by an ATR-Fourier transforms infrared (ATR-FTIR) spectrometer. Wavenumber of FTIR spectra at 719 cm1 indicated the Ti-O-Ti bond. Band gap energies of the films ranged from 3.19-3.29 eV. The photocatalytic activity of the film was tested for removal of gaseous acetone in a closed chamber. Experimental conditions were set as follows: a UV light intensity of approximately 2.7 mW.cm-2, flow rate of 2 L.min-1, and an initial acetone concentration of about 435±20 ppm. While the catalyst dosage was varied from 3% to 15% (wt. cat/wt. film).The degradation rate of acetone increased when increasing dosage of TiO2 from 3% to 10%, then decreased a little bit when increasing the dosage to 15%. The TiO2/LDPE composite film at the dosage of 10% yielded the highest removal efficiency of 75%, followed by the film at the dosage of 15%, 5%, and 3%, respectively.

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