Effective photocatalytic degradation of an azo dye over nanosized Ag/AgBr-modified TiO2 loaded on zeolite

2011 ◽  
Vol 65 (3) ◽  
Author(s):  
Mohsen Padervand ◽  
Mahboubeh Tasviri ◽  
Mohammad Gholami
Keyword(s):  
Photocatalytic Degradation ◽  
Photocatalytic Performance ◽  
Catalyst Concentration ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Textile Dye ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Desorption ◽  
Acid Blue

AbstractZeolite-based photocatalysts were prepared by the sol-gel and deposition methods. The photocatalysts were characterised by X-ray diffraction, nitrogen adsorption-desorption isotherms, FTIR spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectrometry. The activity of the prepared photocatalysts was evaluated by the UV-induced degradation of acid blue 92, a textile dye in common use. The effect of various parameters, such as catalyst concentration, initial dye concentration, thiosulphate concentration and pH, on the rate and efficiency of the photocatalytic degradation of acid blue 92 was investigated. The results showed that each parameter influenced the degradation rate and efficiency in a particular way. It was also found that, under optimised conditions, Ag/AgBr/TiO2/zeolite exhibited the highest photocatalytic performance. A comparison of catalytic activity when exposed to visible light under the same conditions showed that the photocatalysts containing AgBr had the highest activity.

ZnO-SiO2/Laponite Photocatalyst: Kinetic Study on Photocatalytic Decolorization of Methylene Blue

2014 ◽  
Vol 896 ◽  
pp. 541-544
Author(s):  
Is Fatimah ◽  
N. Nunani Yuyun
Keyword(s):  
Methylene Blue ◽  
Energy Dispersive Spectrometry ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photocatalytic Decolorization ◽  
Uv Visible ◽  
Gel Preparation ◽  
Adsorption Desorption

ZnO-SiO2/Laponite was prepared by sol-gel preparation procedure consit of SiO2 pillarization to laponite followed by ZnO dispersion by using zinc acetate as precursor. The obtained material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), diffuse reflectance UV-Visible (DRUV-Vis) and N2 adsorption-desorption analysis. The photocatalytic performance of the amterial in methylene blue decolorization was also investigated. Compared with ZnO-SiO2 nanoparticles, it is concluded that ZnO-SiO2/Laponite possess higher photocatalytic activity which obey Temkin isotherm model.

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.

Preparation of Fe3O4/TiO2 magnetic mesoporous composites for photocatalytic degradation of organic pollutants

2017 ◽  
Vol 75 (7) ◽  
pp. 1523-1528 ◽  
Author(s):  
Hongfeng Zhang ◽  
Xiu He ◽  
Weiwei Zhao ◽  
Yu Peng ◽  
Donglan Sun ◽  
...  
Keyword(s):  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Magnetic Composite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mesoporous Composites ◽  
Uv Lamp ◽  
Adsorption Desorption

Fe3O4/TiO2 magnetic mesoporous composites were synthesized through a sol-gel method with tetra-n-butyl titanate as precursor and surfactant P123 as template. The as-prepared Fe3O4/TiO2 composites were characterized by X-ray diffraction, diffuse reflectance spectroscopy, nitrogen adsorption-desorption isotherm and pore size distribution. The as-synthesized products were applied as photocatalysis for the degradation of Acid Black ATT and tannery wastewater under UV lamp irradiation. Fe3O4/TiO2-8 composites containing Fe3O4 of 8 wt% were selected as model catalysts. The optimal catalyst dosage was 3 g/L in this photocalytic system. The magnetic Fe3O4/TiO2 composites possessed good photocatalytic stability and durability. This approach may provide a platform to prepare a magnetic composite to optimize the catalytic ability.

The Synthesis and Photocatalytic Performance of Samarium Doped Mesoporous Titania

2018 ◽  
Vol 876 ◽  
pp. 15-19
Author(s):  
Jian Wen Shi ◽  
Dan Dan Ma ◽  
Ya Jun Zou
Keyword(s):  
Diffuse Reflectance ◽  
Photocatalytic Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Reflectance Spectroscopy ◽  
Mesoporous Titania ◽  
X Ray Diffraction ◽  
Structure Directing Agent ◽  
X Ray

The meso-porous TiO2 and Sm-doped meso-porous TiO2 were synthesized by a sol-gel method. Polyethylene glycol, with different added content, was added as a structure-directing agent. The prepared meso-porous TiO2 was characterized by nitrogen adsorption, X-ray diffraction and ultraviolet-visible diffuse reflectance spectroscopy, and the photocatalytic performance was evaluated by the decomposition of methyl orange. The results revealed that PEG plays a key role in creating porous structure during the heat-treatment. The photocatalytic performance of TiO2 is improved by adding proper content PEG, and Sm-doping can further promote the photocatalytic performance.

scholarly journals Modification of TiO2 nanoparticles through lanthanum doping and peg templating

2014 ◽  
Vol 8 (4) ◽  
pp. 195-202 ◽  
Author(s):  
Marija Milanovic ◽  
Ljubica Nikolic
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Average Pore ◽  
Lanthanum Doping ◽  
X Ray ◽  
Doped Titania ◽  
Adsorption Desorption

Pure and lanthanum doped titania nanopowders were synthesized through a room temperature sol-gel method using a template of polyethylene glycol (PEG). The progress of the synthesis in terms of phase formation and size of nanoparticles was monitored by X-ray diffraction, FTIR spectroscopy and SEM analysis. After calcination at 450?C in air, the results have shown the presence of small particles crystallized predominantly in the form of anatase phase, with significant agglomeration. Nitrogen adsorption-desorption measurements confirmed that all prepared powders are mesoporous with an average pore diameter in range 3.1-3.8 nm. The addition of lanthanum ions leads to the nanopowders with the highest specific surface (BET) area (203m2/g). The obtained powders were compared to TiO2 prepared without a template.

scholarly journals The impregnation of ZnO onto ZSM-5 derived from red mud for photocatalytic degradation of methylene blue

2022 ◽  
Vol 32 (1) ◽  
Author(s):  
Hellna Tehubijuluw ◽  
Riki Subagyo ◽  
Yuly Kusumawati ◽  
Didik Prasetyoko
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Red Mud ◽  
Diffuse Reflectance Spectroscopy ◽  
Degradation Products ◽  
Nitrogen Adsorption ◽  
Liquid Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Desorption

AbstractPhotocatalytic degradation of Methylene Blue (MB) by zinc oxide/zeolite socony mobile-5 (ZnO/ZSM-5) composites was investigated. The ZSM-5 material was synthesized from red mud by a two-step hydrothermal method to which ZnO loadings at different mass ratios were subsequently performed. Characterizations using X-ray diffraction (XRD), Fourier transform infrared spectroscopy, and scanning electron microscopy were carried out to identify the formation of ZSM-5 and ZnO/ZSM-5. ZSM-5 and ZnO/ZSM-5 have cubic microcrystallite morphologies. ZnO loading in the ZnO/ZSM-5 composites was successfully performed and confirmed by the appearance of wurtzite peaks in the XRD spectra that matched the Joint Committee on Powder Diffraction Standards data. The presence of ZnO in ZSM-5 leading resulted in a decrease in the surface area and pore size as confirming by nitrogen adsorption-desorption isotherm experiments. The band gap of the samples was measured using UV-Vis diffuse reflectance spectroscopy. The optimum photocatalytic degradation of MB was observed at a ZnO loading of 34% w/w dubbed 34-ZnO/ZSM-5. The influence of the initial concentration of MB was also investigated at 80, 90, and 100 mg L− 1 using 34-ZnO/ZSM-5 and ZSM-5. Liquid chromatography–mass spectrometry characterization was performed to analyze the degradation products.

Ferrimagnetic Membranes for Separation of Paramagnetic and Diamagnetic Species

2002 ◽  
Vol 752 ◽  
Author(s):  
Jihye Gwak ◽  
André Ayral ◽  
Vincent Rouessac ◽  
Louis Cot ◽  
Jean-Claude Grenier ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Air Separation ◽  
Magnetic Interactions ◽  
Colloidal Solutions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Desorption

ABSTRACTFor using as separative membranes based on magnetic selectivity, nanoporous ferrimagnetic membranes of maghemite (γ-Fe2O3) and cobalt ferrite (Fe2CoO4) were prepared by the sol-gel route from ferrofluid colloidal solutions. Their magnetic properties were examined by superconductor quantum interference device (SQUID), and their structures and porous textures were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen adsorption-desorption analyses. O2-N2 adsorption and air separation experiments were carried out in order to evidence magnetic interactions in static and dynamic conditions, respectively. A small effect of an external magnetic field on the selectivity of these membranes was observed.

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.

Application of raw and modified Uruguayan clays to phosphate adsorption for water remediation

MRS Advances ◽  
2018 ◽  
Vol 3 (61) ◽  
pp. 3543-3549
Author(s):  
Pablo González ◽  
Andrea C. De Los Santos ◽  
Jorge R. Castiglioni ◽  
María A. De León
Keyword(s):  
Nitrogen Adsorption ◽  
Pillared Clay ◽  
Water Remediation ◽  
Phosphate Adsorption ◽  
X Ray Diffraction ◽  
Order Model ◽  
Freundlich Model ◽  
X Ray ◽  
First Order ◽  
Adsorption Desorption

ABSTRACTA raw clay from Uruguay was modified with aluminium to obtain an aluminium pillared clay (Al-PILC). The solids were characterized by scanning electron microscopy, X-ray diffraction and nitrogen adsorption-desorption isotherms. The Al-PILC retained the typical laminar structure of montmorillonite. The specific surface area and the microporous volume of the Al-PILC, 235 m2 g-1 and 0.096 cm3 g-1, respectively, were much higher than those of the clay. The phosphate adsorption capacity of the Al-PILC was higher than those of the clay. The phosphate adsorption kinetic followed the pseudo-first-order model for both, the clay and the Al-PILC, and the phosphate adsorption isotherm for the Al-PILC fit the Freundlich model.

scholarly journals An Ultrasound Application for TiO2 Photocatalytic Degradation of Methyl Orange

2021 ◽  
Author(s):  
Xianzhen Diao ◽  
Jin XU ◽  
Yufei WANG
Keyword(s):  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Methyl Orange Solution ◽  
X Ray Diffraction ◽  
Doping Amount ◽  
Nickel Doping ◽  
Ultrasound Application ◽  
Ultrasound Technology

Nanometer TiO2 photocatalysts were prepared by the sol–gel method. The catalysts were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, ultraviolet-visible spectroscopy, and other techniques. Methyl orange solution was used for the degradation of the organic material and ultrasonic technology was used to determine the photocatalytic performance of the catalysts. The results show that the photocatalytic performance of the Ni-N-TiO2 is clearly improved under ultrasonic conditions. The TiO2 photocatalytic degradation effect is optimal at a catalyst concentration of 0.3 g/L, an initial concentration of the organic matter of 0.03 mmol/L, a nickel-doping amount of 2 mol %, and a nitrogen-doping amount of 15 mol %. The use of ultrasound technology in combination with photocatalysis has a positive effect and results in a TiO2 degradation rate of methyl orange of 95 % after 3 h.

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