scholarly journals Effect of the Mg/Al Ratio on Activated Sol-Gel Hydrotalcites for Photocatalytic Degradation of 2,4,6-Trichlorophenol

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Esthela Ramos-Ramírez ◽  
Norma L. Gutiérrez-Ortega ◽  
Francisco Tzompantzi-Morales ◽  
Gloria A. Del Ángel ◽  
Claudia Martínez-Gómez ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Mixed Oxides ◽  
Thermal Evolution ◽  
Paper Industry ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Good Efficiency ◽  
X Ray ◽  
Mixed Oxide Catalysts ◽  
Surface Areas

Currently, interest has grown in finding effective solutions for the treatment of water pollution by toxic compounds. Some of the latter that have acquired importance are phenols and chlorophenols, due to their employment in the manufacture of pesticides, insecticides, cords of wood, paper industry, among others. The problem is rooted in that these compounds are very persistent in the environment because they are partially biodegradable and cannot be photodegraded directly by sunlight. Chlorophenols are extremely toxic, especially 2,4,6-trichlorophenol, which is potentially carcinogenic. In this work, Mg/Al-mixed oxide catalysts were obtained from the thermal treatment of hydrotalcite-type materials, synthesized by sol-gel method with different Mg/Al ratios. Hydrotalcites and Mg/Al-mixed oxides were physicochemically characterized by X-ray diffraction, thermal analysis (DTA and TGA), and N2 physisorption. The results were obtained on having proven the photocatalytic degradation of 2,4,6-trichlorophenol as a pollutant model by water. The catalysts obtained present the hydrotalcite phase with thermal evolution until achieving Mg/Al-mixed oxides at 500°C. The catalysts are of mesoporous materials and exhibiting large surface areas. The catalysts demonstrated good photocatalytic activity with good efficiency, reaching degradation percentages with Mg/Al = 1, 2, 4, 5, and 7 ratios of 94.2, 92.5, 86.2, 84.2, and 63.9%, respectively, until achieving mineralization.

scholarly journals Bulk Versus Surface Modification of Alumina with Mn and Ce Based Oxides for CH4 Catalytic Combustion

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1771 ◽  
Author(s):  
Stefan Neatu ◽  
Mihaela M. Trandafir ◽  
Adelina Stănoiu ◽  
Ovidiu G. Florea ◽  
Cristian E. Simion ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Combustion ◽  
Mixed Oxides ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Catalytic Combustion Of Methane ◽  
Adsorption Desorption

This study presents the synthesis and characterization of lanthanum-modified alumina supported cerium–manganese mixed oxides, which were prepared by three different methods (coprecipitation, impregnation and citrate-based sol-gel method) followed by calcination at 500 °C. The physicochemical properties of the synthesized materials were investigated by various characterization techniques, namely: nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and H2–temperature programmed reduction (TPR). This experimental study demonstrated that the role of the catalytic surface is much more important than the bulk one. Indeed, the incipient impregnation of CeO2–MnOx catalyst, supported on an optimized amount of 4 wt.% La2O3–Al2O3, provided the best results of the catalytic combustion of methane on our catalytic micro-convertors. This is mainly due to: (i) the highest pore size dimensions according to the Brunauer-Emmett-Teller (BET) investigations, (ii) the highest amount of Mn4+ or/and Ce4+ on the surface as revealed by XPS, (iii) the presence of a mixed phase (Ce2MnO6) as shown by X-ray diffraction; and (iv) a higher reducibility of Mn4+ or/and Ce4+ species as displayed by H2–TPR and therefore more reactive oxygen species.

scholarly journals Synthesis Photocatalytic and Antibacterial Activities of Nickle Doped Tio2 Nanoparticles

2018 ◽  
Vol 34 (6) ◽  
pp. 3140-3144
Author(s):  
Ritu Vershney ◽  
Komal Chelaramani ◽  
Arpan Bhardwaj ◽  
Nayma Siddiqui ◽  
Suresh Kumar Verma
Keyword(s):  
Photocatalytic Degradation ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Antibacterial Activities ◽  
X Ray Diffraction ◽  
Zone Of Inhibition ◽  
Time Duration ◽  
X Ray ◽  
Gel Technique ◽  
Doped Titania

The synthesis of Ni doped titania (TiO2) nanoparticles were achieved via simple novel sol gel technique, in which Titanium-n-butoxide and NiCl2 were taken as precursors. Effect of different wt% of dopant in TiO2 was studied on photocatalytic degradation of Aniline blue and Toluidine Blue. The study suggested the increased photocatalytic degradation with increased time duration. The synthesized samples were analyzed by surface electron microscopy (SEM) and X-ray diffraction studies. The antibacterial activity was investigated against Gram-positive Staphylococcus aureus bacteriae. Studies revealed that on increasing the dopant concentration, the diameter of zone of inhibition also increased upto 1.5 wt%.

scholarly journals Preparation and Photocatalytic Activity of TiO2/Fine Char for Removal of Rhodamine B

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mingjie Ma ◽  
Weijie Guo ◽  
Zhengpeng Yang ◽  
Shanxiu Huang ◽  
Guanyu Wang
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Uv Light ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
Light Illumination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Light Irradiation

TiO2/fine char (FC) photocatalyst was prepared via sol-gel method with tetrabutyl titanate as the precursor and FC as the carrier. The structural property of TiO2/FC photocatalyst was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the photocatalytic activity of TiO2/FC was evaluated by photocatalytic degradation of rhodamine B (RhB) aqueous solution under UV light irradiation. The results showed that TiO2was successfully coated on the surface of FC, and the TiO2/FC photocatalyst had better photocatalytic efficiency and stability for degradation of RhB under UV light illumination as compared to that of the pure TiO2and FC. The study provided a novel way for the application of FC to the photocatalytic degradation of organic wastes.

scholarly journals Sol-Gel Synthesized Semiconductor Oxides in Photocatalytic Degradation of Phenol

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Maria K. Cherepivska ◽  
Roman V. Prihod’ko
Keyword(s):  
Photocatalytic Degradation ◽  
Sol Gel ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Semiconductor Oxides ◽  
Titanium Dioxide Sample ◽  
Vis Spectroscopy ◽  
Physical And Chemical ◽  
And Chemical Properties

Effectiveness of photocatalytic degradation of phenol in aqueous solution using semiconductor oxides (SO) prepared by a sol-gel method was examined. The physical and chemical properties of synthesized catalysts were investigated by X-ray diffraction (XRD), diffuse reflectance UV-Vis spectroscopy (DRS), and N2-adsorption measurements. The optimal conditions of the photocatalytic degradation of phenol using prepared titanium dioxide sample were defined.

scholarly journals Effect of Sr on the properties of Ce-Zr-La mixed oxides

2006 ◽  
Vol 71 (3) ◽  
pp. 285-291 ◽  
Author(s):  
Richuan Rao ◽  
LI Lianyong ◽  
LI Fengyi
Keyword(s):  
Mixed Oxide ◽  
Storage Capacity ◽  
Mixed Oxides ◽  
Sol Gel ◽  
Oxygen Storage Capacity ◽  
Oxygen Storage ◽  
X Ray Diffraction ◽  
Pulse Technique ◽  
X Ray ◽  
Good Thermal Stability

Ce-Zr-La-Sr mixed oxides, with different Sr contents, were prepared by the sol-gel method. In a flow-system microreactor, the reduction properties and the oxygen storage capacity (OSC) of the Ce-Zr-La-Sr mixed oxides were investigated by a temperature programmed reduction (TPR) and a pulse technique. It was shown that the properties of the Ce-Zr-La mixed oxides depend on the Sr content and that the optimum Sr content in the Ce-Zr-La-Sr mixed oxide is 3 mol%. The Ce-Zr-La-Sr mixed oxides doped with 3 mol% Sr (Ce0.52Zr0.4La0.05Sr0.03O1.945) has the largest specific surface area and better reduction properties and oxygen storage capacity in comparison to the other investigated samples. The XRD results of the Ce-Zr-La-Sr mixed oxides showed that their X-ray diffraction patterns are well in agreement with that of fluorite-type CeO2 with Sr ions incorporated into the Ce-Zr-La mixed oxide structures. With increasing calcination temperature, the intensity of the X-ray diffraction peaks increased, but no new peaks were observed. All of these indicate that the synthesized samples had good thermal stability.

scholarly journals PHOTOCATALYTIC DEGRADATION OF PARAQUAT USING N-TiO2/SiO2 UNDER VISIBLE LIGHT

2018 ◽  
Vol 55 (4C) ◽  
pp. 277 ◽  
Author(s):  
Nguyen Thi Phuong Mai
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Diffuse Reflectance Spectroscopy ◽  
Organic Pollutant ◽  
Sol Gel ◽  
Oxygen Demand ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Illumination Time ◽  
X Ray

In the present paper, photocatalytic degradation of paraquat using N-TiO2/SiO2 with different molar ratio of titanium: nitrogen (Ti:N) under visible light was investigated. The catalyst was prepared via immersed SiO2 in N-TiO2. N-TiO2 was synthesized by sol-gel method.  The N-TiO2/SiO2 catalyst was characterized using X-ray diffraction, UV diffuse reflectance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy. The results from characterizations indicated that N-doped anatase TiO2 had a 20-25 nm size. Degradation of paraquat, at an initial concentration of 10 mg/L was determined by UV-Vis. Chemical oxygen demand (COD) was used for process performance. Based on the COD tests, the COD values in residual paraquat was lower than that in initial paraquat concentration after 8 hours illumination of visible light. Moreover, the experiment’s results indicated that 80% of paraquat was degraded within 8 h of illumination time. These results showed that N-TiO2/SiO2 with molar Ti:N=2:1 gives the highest degradation efficiency of paraquat under visible light. This catalyst was stable and reusable suggesting it can be applied to treat organic pollutant in water. 

scholarly journals Enhancement of Photocatalytic Activity of ZnO/SiO2by Nanosized Pt for Photocatalytic Degradation of Phenol in Wastewater

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
R. M. Mohamed ◽  
M. A. Barakat
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Surface Area ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Phenol Degradation ◽  
Synthetic Wastewater ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

ZnO- nanoparticles were synthesized by a sol-gel technique from and tetraethyl orthosilicate (TEOS). The synthesized samples were further modified by nanosized Pt from H2PtCl6solution through photoassisted deposition (PAD) and impregnation (Img) routes. The obtained samples were characterized by a series of techniques including X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy, N2adsorption, extended X-ray absorption fine structure (EXAFS), and transmission electron microscopy (TEM). The photocatalytic activity of the Pt-ZnO/ was evaluated by photocatalytic degradation of phenol in synthetic wastewater under UV-irradiation. Results obtained revealed that the surface area and the photocatalytic activity of the prepared samples were increased in the order ZnO/ < PAD: Pt-ZnO/ < img: Pt-ZnO/. The surface area decreased from 480 to 460 and 450 m2/g, while the efficiency of the phenol degradation increased from 80 to 85 and 100%, with the ZnO/, Img: Pt-ZnO-, and PAD: Pt-ZnO- samples, respectively.

Fabrication of PST Nanotubes with Sol-Template Method and its Usage in Aluminum Foil Capacitor

2010 ◽  
Vol 148-149 ◽  
pp. 887-892 ◽  
Author(s):  
Xiao Hua Sun ◽  
Xiu Neng Li ◽  
Sheng Gang Zhou ◽  
Jun Zou
Keyword(s):  
Thermal Evolution ◽  
Sol Gel ◽  
Aluminum Foil ◽  
Transformation Process ◽  
X Ray Diffraction ◽  
Aao Template ◽  
Nanotube Array ◽  
X Ray ◽  
Compound Method ◽  
Precision Impedance Analyzer

Lead strontium titanate (PST) nanotubes were fabricated with sol-gel method on AAO template. Thermal evolution and phase transformation process of PST were characterized by Thermogravimetry and Differential thermal analysis (TG/DTA) and X-ray diffraction (XRD). It was found that PST began to crystallize at 560°C and became perovskite structure without other phases. The morphology and structure of PST nanostructures was characterized by SEM and TEM. The capacitor of AAO and PST-AAO compound aluminum foil annealed at different temperature were tested with precision impedance analyzer. It revealed that the microstructures of PST were polycrystalline nanotube array and the capacitor of compound aluminum foil was increased for PST existing in the AAO, which indicated that this compound method could improve the capacitor of aluminum foil effectively.

Photocatalytic Degradation of Methyl Orange on Ce-TiO2 under Visible Light Irradiation

2012 ◽  
Vol 529 ◽  
pp. 528-531
Author(s):  
Zhi Gang Duan ◽  
Qin Yu Li ◽  
Xv Yun Zhao ◽  
Zhi Ming Peng ◽  
Shen Hua Zhang
Keyword(s):  
Photocatalytic Degradation ◽  
Sol Gel ◽  
Threshold Value ◽  
Absorption Efficiency ◽  
Doping Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Visible ◽  
Doping Ratio ◽  
Degradation Of Methyl Orange

In this article, the Ce-TiO2have been prepared by Sol-gel method to study the photocatalytic activity of Ce-TiO2photocatalyst.The effects of doping ratio on the crystal structure, Absorption spectrum and photocatalytic degradation of methylene were studied and characterized by X-ray diffraction and UV–visible spectrometer.The results indicate:with the increase of the CeO2doping content to TiO2, the absorption efficiency of the Ce-TiO2correspondingly increases. When CeO2doping content is 50%, the absorbing wavelength threshold value reaches the highest 520nm .The rate of degradation on methylene of the sample is higher than that of Degause P25 after 4h irradiated by sunshine. When the ratio is 11%, the degradation rate reaches the highest 87%. The paper systemical investigate the relationships between CeO2doping tatio, microstructure, and macro-performances of Ce-TiO2for the first time.These results provide guild for the future inductrical production of efficient photocatalyst.

scholarly journals USE OF NANOSIZED CHROMIUM DOPED TiO2 SUPPORTED ON ZEOLITE FOR METHYLENE BLUE DEGRADATION

2010 ◽  
Vol 10 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Aarti Ameta ◽  
Indu Bhati ◽  
Rakshit Ameta ◽  
Suresh C. Ameta
Keyword(s):  
Methylene Blue ◽  
Titanium Dioxide ◽  
Photocatalytic Degradation ◽  
Sol Gel ◽  
Blue Dye ◽  
Photocatalytic Reaction ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Methylene Blue Degradation ◽  
X Ray

The photocatalytic degradation of methylene blue dye under visible light has been investigated using chromium modified titanium dioxide supported on zeolite (Cr-TiO2/zeolite). The photocatalyst was prepared by sol-gel method and characterized by X-ray diffraction and SEM. The rate of photodegradation of dye was monitored spectrophotometrically. The effect of pH, dye concentration, amount of photocatalyst and intensity of light on the rate of photocatalytic reaction was observed. The results showed that the use of Cr-doped TiO2 increased the rate of photocatalytic degradation of methylene blue as compared to untreated TiO2. The photocatalytic mechanism of Cr-TiO2 catalyst has been tentatively discussed.   Keywords: Methylene blue, zeolite, chromium, photocatalytic degradation

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