Search for: photocatalytic-performance
Total 40 records
Mixed ammonium silver phosphomolybdate salt nanostructures; solid state synthesis, characterization of driving agent role and photocatalytic property, Article Materials Letters ; Volume 161 , December , 2015 , Pages 464-467 ; 0167577X (ISSN) ; Iraji Zad, A ; Imani, M ; Sharif University of Technology
A green mechanochemical technique has been developed for the synthesis of mixed ammonium silver phosphomolybdate salt, (NH
4) 1.6Ag 1.4PMo 12O 40.4H 2O with sheet-like nanostructure. The reaction was prompted using acetamide/NH 4NO 3 at room temperature. The change of driving agent to urea at the same conditions led to an epitaxial growth of hierarchical microstructure of this polyoxoanion. The morphological and structural features of the prepared specimens were discussed in detail. The photocatalytic performance of the resulting nanosheets for removing 4-nitrophenol (4-NP) in water under visible light...
Article Surface and Coatings Technology ; Volume 288 , 2016 , Pages 144-150 ; 02578972 (ISSN) ; Mohaghegh, N ; Sharif University of Technology
RGO/Ag/TiO2-nanotubes/Ti plates with high photocatalytic activity were fabricated via electrochemical reduction of graphene oxide on Ag/TiO2-nanotubes. The loading of silver nanoparticles was carried out by electroless reduction of Ag1+ onto TiO2 nanotubes previously formed by anodizing titanium. Microstructure studies show that reduced graphene oxide (RGO) layers having high surface area have been deposited on the as-prepared Ag/TiO2-nanotubes, where nanoparticles of Ag had grown on the walls of TiO2-nanotubes. The results of photocatalytic experiments demonstrate that the RGO/Ag/TiO2-nanotubes/Ti plate exhibits significantly enhanced photocatalytic activity for the photocatalytic...
Article Chemical Physics Letters ; Volume 751 , 2020 ; Rasteh, M ; Gholami, M. R ; Sharif University of Technology
Elsevier B.V 2020
Ag2O particles were loaded on the surface of ZnCr-LDH via an anion-exchange precipitation approach by using privilege of the memory trace feature of the LDH-type materials. The structural properties of the resulted photocatalyst were explored by different spectroscopic and microscopic methods. The photocatalytic studies on acid black degradation ascertained that the prepared Ag2O/ZnCr-LDH nanocomposite represented an observably increased degradation performance of organic pollutants compared with pure Ag2O and ZnCr-LDH. This improved photocatalytic performance can be ascribed to the enhanced surface area, good order distributing of particles and effective charge carrier transfer and...
Towards developing efficient metalloporphyrin-based hybrid photocatalysts for CO2reduction; an: ab initio study, Article Physical Chemistry Chemical Physics ; Volume 22, Issue 40 , 2020 , Pages 23128-23140 ; Papior, N ; Zahedi, M ; Moshfegh, A. Z ; Sharif University of Technology
Royal Society of Chemistry 2020
A series of thiophene-based donor-acceptor-donor (D-A-D) oligomer substituted metalloporphyrins (MPors) with different 3d central metal-ions (M = Co, Ni, Cu, and Zn) were systematically investigated to screen efficient hybrid photocatalysts for CO2 reduction based on density functional theory (DFT) and time-dependent DFT simulations. Compared with base MPors, the newly designed hybrid photocatalysts have a lower bandgap energy, stronger and broader absorption spectra, and enhanced intermolecular charge transfer, exciton lifetime, and light-harvesting efficiency. Then, the introduction of D-A-D electron donor (ED) groups into the meso-positions of MPors is a promising method for the...
Heterogeneous photocatalytic degradation of organic pollutant in aqueous solutions by S-scheme heterojunction in nickel molybdate nanocomposites, Article Journal of Environmental Chemical Engineering ; Volume 9, Issue 5 , 2021 ; 22133437 (ISSN) ; Kohantorabi, M ; Sharif University of Technology
Elsevier Ltd 2021
A novel ɑ-NiMoO4/ɑ-MoO3 binary nanocomposite was fabricated by using facile method. The fabricated nanocomposite was characterized by various techniques, and the photocatalytic activity was evaluated in degradation of Acid blue 92 dye. Among of as-made photocatalysts with various weight ratios of ɑ-MoO3, ɑ-NiMoO4/ɑ-MoO3 (1:5%w/w) exhibited the best photocatalytic performance, and selected as optimum photocatalyst. Under optimum reaction conditions ([dye] = 10 mg L−1, [catalyst] = 200 mg L−1, and pH = 7.0), complete removal efficiency was obtained within 100 min. Also, the first-order rate constant value of reaction in the presence of ɑ-NiMoO4/ɑ-MoO3 was calculated to be 0.032 min−1 that was...
Removal of an organic pollutant from waste water by photocatalytic behavior of AgX/TiO2 loaded on mordenite nanocrystals, Article Research on Chemical Intermediates ; Volume 38, Issue 8 , 2012 , Pages 1975-1985 ; 09226168 (ISSN) ; Salari, H ; Ahmadvand, S ; Gholami, M. R ; Sharif University of Technology
Mordenite (MOR) nanocrystals were synthesized using the hydrothermal method. Sol-gel and deposition methods were utilized to modify the zeolite surface with TiO2 and then AgBr or AgCl particles. Photocatalysts were characterized by using X-ray diffraction, Brunauer-Emmett-Teller (BET), and scanning electron microscopy techniques. Activity was evaluated by photodegradation of Acid Blue 92 as an azo dye. The effect of silver halide deposition on the photocatalytic behavior of the prepared nanocomposites was studied under both ultraviolet (UV) and visible light, and the results were compared. The results showed that AgCl/TiO2/MOR was more active under UV, while with visible source,...
Protein degradation and RNA efflux of viruses photocatalyzed by graphene-tungsten oxide composite under visible light irradiation, Article Journal of Physical Chemistry C ; Volume 116, Issue 17 , 2012 , Pages 9653-9659 ; 19327447 (ISSN) ; Choobtashani, M ; Ghaderi, E ; Sharif University of Technology
Graphene-tungsten oxide composite thin films with sheetlike surface morphology were fabricated and applied in photoinactivation of viruses under visible light irradiation. Using X-ray photoelectron spectroscopy, it was found that the chemically exfoliated graphene oxide sheets incorporated in the tungsten oxide film reduced through a visible light photocatalytic reduction. In addition, annealing the films at 450 °C in air resulted in formation of W-C and W-O-C bonds to obtain graphene-tungsten oxide composite films. The composite films fabricated by this method showed an excellent visible light photocatalytic performance in photoinactivation of bacteriophage MS2 viruses, as compared to...
Effects of morphology on photocatalytic performance of Zinc oxide nanostructures synthesized by rapid microwave irradiation methods, Article Superlattices and Microstructures ; Volume 51, Issue 4 , 2012 , Pages 512-522 ; 07496036 (ISSN) ; Ghorbani, H ; Paravar, A ; Samberg, J. P ; Kajbafvala, E ; Sadrnezhaad, S. K ; Sharif University of Technology
In this study, two different chemical solution methods were used to synthesize Zinc oxide nanostructures via a simple and fast microwave assisted method. Afterwards, the photocatalytic performances of the produced ZnO powders were investigated using methylene blue (MB) photodegradation with UV lamp irradiation. The obtained ZnO nanostructures showed spherical and flower-like morphologies. The average crystallite size of the flower-like and spherical nanostructures were determined to be about 55 nm and 28 nm, respectively. X-ray diffraction (XRD), scanning electronic microscopy (SEM), Brunauer-Emmett-Teller (BET), room temperature photoluminescence (RT-PL) and UV-vis analysis were used for...
A strategy for single-step elaboration of V2O 5-grafted TiO2 nanostructured photocatalysts with evenly distributed pores, Article Journal of Alloys and Compounds ; Volume 509, Issue 21 , 2011 , Pages 6236-6241 ; 09258388 (ISSN) ; Molaei, R ; Moshfegh, A. Z ; Golestani-Fard, F ; Sharif University of Technology
V2O5-TiO2 nanostructured porous layers were grown through micro arc oxidation of titanium in vanadate containing electrolytes. This study sheds light on the effect of the electric current type on the photocatalytic performance of the layers. Surface morphology of the layers was investigated by SEM. The results revealed a porous structure with a pores size of 30-180 nm depending on the frequency and the duty cycle. A uniform porous structure was obtained under the pulse-DC regime. Topographical investigations revealed a rough surface which is favorable for catalytic applications. Our XRD and XPS results showed that the layers consisted of anatase, rutile, and vanadium oxide phases whose...
Article Journal of Materials Engineering and Performance ; Volume 24, Issue 7 , July , 2015 , Pages 2757-2763 ; 10599495 (ISSN) ; Sadrnezhaad, S. K ; Sharif University of Technology
Springer New York LLC 2015
Photocatalysts that are used for waste water treatment are often suspended in the waste water during processing and then must be removed from the water after treatment. To reduce the post-degradation expenses and time, separation is facilitated by an immobilization process. The effect of immobilized TiO
2 geometries on the photocatalytic behavior of the photocatalyst is investigated in this work. Powder, fiber, film, and network-shaped TiO 2 nanocatalysts were produced by using different templates. The cellulose fiber and ceramic templates were used as substrates for fiber and film/network geometry production. The products were characterized by x-ray diffraction (XRD),...
Article Acta Physica Polonica A ; Volume 127, Issue 6 , 2015 , Pages 1727-1731 ; 05874246 (ISSN) ; Safa, S ; Akhavan, O ; Sharif University of Technology
Various morphologies of monoclinic CuO powders were synthesized by hydrothermal treatment of copper nitrate, copper acetate or copper sulfate. The synthesized samples were characterized by scanning electron microscopy, X-ray diffractometry, the Fourier transform infrared spectroscopy, and diffuse reflectance spectrophotometry. Antibacterial activity of the samples was studied against Escherichia coli bacteria in dark and under visible light irradiation. Although the different precursors yielded the same band gap energies (≈1.6 eV) for the synthesized CuO samples, they resulted in various morphologies (hierarchy of stabilized micro/nanostructures), specific surface areas, concentrations of...
Visible light photo-induced antibacterial activity of CNT-doped TiO 2 thin films with various CNT contents, Article Journal of Materials Chemistry ; Volume 20, Issue 35 , Jun , 2010 , Pages 7386-7392 ; 09599428 (ISSN) ; Azimirad, R ; Safa, S ; Larijani, M. M ; Sharif University of Technology
Carbon nanotube (CNT)-doped TiO2 thin films with various CNT contents were synthesized by sol-gel method for visible light photoinactivation of Escherichia coli bacteria. Post annealing of the CNT-doped TiO2 thin films at 450 °C resulted in anatase TiO2 and formation of Ti-C and Ti-O-C carbonaceous bonds in the film. By increasing the CNT content, the thin films could further inactivate the bacteria in the dark. Meanwhile, as the CNT content increased from zero to 40 wt% the effective optical band gap energy of the CNT-doped TiO2 thin films annealed at 450 °C decreased from 3.2-3.3 to less than ∼2.8 eV providing light absorption in the visible region. Concerning this, visible light...
Article Journal of Materials Science and Technology ; Volume 26, Issue 6 , June , 2010 , Pages 535-541 ; 10050302 (ISSN) ; Irajizad, A ; Taghavinia, N ; Rahman, M ; Ahadian, M. M ; Sharif University of Technology
The influence of an externally applied bias on photocatalytic performance of crystallized TiO2/Ti nanotubular electrode formed by anodization in fluoride-based electrolyte were investigated and compared to the behavior of multiporous TiO2 electrode. The photoelectrocatalytic oxidation behavior of methanol over the nanotubular electrode has been studied by measuring photocurrent response, potentiodynamic polarization spectroscopy and using electrochemical impedance spectroscopy (EIS). It was found that the photoelectrocatalytic oxidation and the charge transfer rate constant of reaction on TiO2/Ti nanotubular electrode can significantly be increased by applying electrochemical bias. Moreover,...
How photocatalytic activity of the MAO-grown TiO2 nano/micro-porous films is influenced by growth parameters?, Article Applied Surface Science ; Volume 256, Issue 13 , 2010 , Pages 4253-4259 ; 01694332 (ISSN) ; Golestani Fard, F ; Moshfegh, A. Z ; Sharif University of Technology
Pure titania porous layers consisted of anatase and rutile phases, chemically and structurally suitable for catalytic applications, were grown via micro-arc oxidation (MAO). The effect of applied voltage, process time, and electrolyte concentration on surface structure, chemical composition, and especially photocatalytic activity of the layers was investigated. SEM and AFM studies revealed that pore size and surface roughness of the layers increased with the applied voltage, and the electrolyte concentration. Moreover, the photocatalytic performance of the layers synthesized at medium applied voltages was significantly higher than that of the layers produced at other voltages. About 90% of...
Enhancing the photocatalytic performance of Ag3PO4 by incorporating g-C3N4 and MWCNTs: Optimisation of removal of Acid Blue 92, Article Progress in Reaction Kinetics and Mechanism ; Volume 41, Issue 3 , 2016 , Pages 277-288 ; 14686783 (ISSN) ; Armandsefat, F ; Mohaghegh, N ; Ahmadinasab, N ; Sharif University of Technology
Science Reviews 2000 Ltd 2016
The main aim of the present study was to enhance the degradation capacity of Acid Blue 92 (AB92) by visible-light-active Ag3PO4 nanocomposites based on g-C3N4 and Multiwalled Carbon Nanotubes (MWCNTs). The nanocomposites were fabricated through a tunable in situ deposition method. The properties of the resulting samples were investigated by X-ray diffraction, scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy. The photocatalytic activity results revealed that the Ag3PO4/g-C3N4 heterojunction inorganic/organic composite exhibited an improvement in both efficiency and the rate of AB92 photodegradation in comparison with the others. The enhanced photocatalytic...
Plasmon enhanced photocatalytic activity of Au@TiO2-graphene nanocomposite under visible light for degradation of pollutants, Article Materials Research Bulletin ; Volume 87 , 2017 , Pages 40-47 ; 00255408 (ISSN) ; Hashemian, S. J ; Alamolhoda, A. A ; Gocheva, I ; Rahman Setayesh, S ; Sharif University of Technology
Elsevier Ltd 2017
Au@TiO2-Graphene (GR) nanocomposite was prepared using photocatalytic reduction method. TiO2-GR nanocomposite was synthesized under UV irradiation of deaerated ethanolic suspension of TiO2. The nanocomposite was calcined at 400∘C followed by loading of highly dispersed Au nanoparticles throughout the deposition-precipitation method. The Au@TiO2/GR was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, diffuse reflectance spectroscopy, transmission electron microscope and the BET surface area measurements. It was found that Au-TiO2-GR and TiO2-GR nanoparticles have smaller crystalline size and higher surface area than pure TiO2. Presence of highly dispersed Au nanoparticles...
Preparation and characterization of a new CdS–NiFe2O4/reduced graphene oxide photocatalyst and its use for degradation of methylene blue under visible light irradiation, Article Research on Chemical Intermediates ; Volume 44, Issue 10 , 2018 , Pages 5953-5979 ; 09226168 (ISSN) ; Kaveh, R ; Ozkar, S ; Akbayrak, S ; Sharif University of Technology
In this paper, CdS nanoparticles as a visible light active photocatalyst were coupled by NiFe2O4 and reduced graphene oxide (rGO) to form CdS–NiFe2O4/rGO nanocomposite by facile hydrothermal methods. The CdS–NiFe2O4/rGO nanocomposite shows enhanced photocatalytic activity for the degradation of methylene blue (MB) under visible light illumination. In addition to improved photocatalytic performance, this prepared nanocomposite shows increased photostability and is magnetically separable from the aqueous media. The degradation rate constant (kapp) of the optimized photocatalyst, i.e. CdS–NiFe2O4 (0.05)/rGO 25 wt% nanocomposite, was higher than the corresponding CdS and NiFe2O4 nanoparticles by...
Engineering a highly dispersed core@shell structure for efficient photocatalysis: a case study of ternary novel BiOI@MIL-88A(Fe)@g-C3N4 nanocomposite, Article Materials Research Bulletin ; Volume 106 , 2018 , Pages 93-102 ; 00255408 (ISSN) ; Gholami, M. R ; Sharif University of Technology
Ternary novel BiOI@MIL-88A(Fe)@g-C3N4 nanocomposite with core@shell structure was successfully synthesized by hydrothermal method. fabricated photocatalysts were characterized and results confirmed the formation of MIL-88A(Fe)@g-C3N4 core@shell structure and subsequently BiOI decoration on the surface of MIL-88A(Fe)@g-C3N4. Photocatalytic performances of prepared samples were investigated for degradation of Acid Blue 92 (AB92), Rhodamine B (RhB) and phenol under visible irradiation. It is clearly demonstrated that the as-prepared ternary BiOI@MIL-88A(Fe)@g-C3N4 composites exhibits exceptional visible-light photocatalytic activities for cationic, anionic as well as neutral pollutant molecules...
Comparison of various anodization and annealing conditions of titanium dioxide nanotubular film on MB degradation, Article EPJ Applied Physics ; Volume 47, Issue 1 , 2009 ; 12860042 (ISSN) ; Iraji Zad, A ; Ahadian, M. M ; Taghavinia, N ; Dolati, A ; Sharif University of Technology
In this study the influence of morphology of vertically oriented titanium oxide nanotube arrays (TNTAs) on their photocatalytic activities was investigated. To obtain nanotubes with different morphologies, they were prepared at different anodization voltages. The size of TNTAs were measured using SEM images and also determined based on a non-destructive optical method; We demonstrate how the tubular geometry of the TNTAs can be used to adjust the optical and also the wetting properties of them and how these properties affect the performance of the nanostructure in further applications as a photocatalyst. To investigate their potentials for environmental applications, the photocatalytic...
Application of nanostructured aluminium titanate (Al2TiO5) photocatalyst for removal of organic pollutants from water: Influencing factors and kinetic study, Article Materials Chemistry and Physics ; Volume 256 , 2020 ; Soltaninejad, M ; Zekavat, M ; Bakhshandeh, F ; Madaah Hosseini, H. R ; Amutha, C ; Ramakrishna, S ; Sharif University of Technology
Elsevier Ltd 2020
In this study, aluminum titanate (Al2TiO5)-based nanostructure with the outstanding photocatalytic performance was prepared via the simple citrate sol-gel method. The effects of thee operational variables such as pH, temperature, catalyst dosage, and initial dye concentration on the photodegradation efficiency of methylene blue (MB) were explored in some details. The results showed that compared to TiO2, AT benefits a superior photocatalytic activity due to its narrow band gap (2.88 eV) and low recombination rate of charge carriers. Increasing the wastewater temperature from 25 to 60 °C can improve the degradation percent from 22.15 to 52%. Based on the thermokinetic calculations, the...