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A comparative study on photoelectrochemical activity of ZnO/TiO2 and TiO2/ZnO nanolayer systems under visible irradiation
, Article Solar Energy ; Volume 85, Issue 9 , 2011 , Pages 1972-1978 ; 0038092X (ISSN) ; Yousefi, M ; Moshfegh, A. Z ; Sharif University of Technology
Abstract
TiO2/ZnO and ZnO/TiO2 nanolayer thin films were synthesized using sol-gel method. Optical analysis revealed high transmittance of the films in the visible range with almost the same bandgap energy for the both systems. XPS technique shows stoichiometric formation of TiO2 and ZnO on the surface of TiO2/ZnO and ZnO/TiO2 layers, respectively. According to AFM observations and its data analysis, the TiO2/ZnO films exhibited a higher surface roughness and more effective interfaces with electrolyte during redox reactions. Based on photoelectrochemical measurements, TiO2/ZnO nanolayer photoanode possesses a lower charge transfer resistance and higher transient time for charge carriers (e- and h+)...
Supported copper and cobalt oxides on activated carbon for simultaneous oxidation of toluene and cyclohexane in air
, Article RSC Advances ; Volume 5, Issue 7 , Dec , 2015 , Pages 5107-5122 ; 20462069 (ISSN) ; Khorasheh, F ; Shayegan, J ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
Copper and cobalt oxides supported on almond shell derived activated carbon (AC) with different loadings were synthesized by sequential and co-deposition-precipitation methods leading to Cu(shell)/Co(core)/AC, Co(shell)/Cu(core)/AC and Cu-Co(mixed)/AC catalysts that were subsequently used for catalytic oxidation of gaseous mixtures of toluene and cyclohexane in air in a tubular flow reactor. The catalysts and the support were characterized by Boehm test, Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy...
TiO2 nanotubular fibers sensitized with CdS nanoparticles
, Article EPJ Applied Physics ; Volume 50, Issue 2 , 2010 ; 12860042 (ISSN) ; Taghavinia, N ; Aghabozorg, H. R ; Iraji Zad, A ; Sharif University of Technology
Abstract
In this study TiO2 nanotubular fibers were prepared and subsequently loaded with CdS nanoparticles to obtain visible light activate nanofibers with modified structure. Preparation of TiO2 fibers was based on templating method and Liquid phase deposition technique (LPD) with cellulose fibers as templates. Using LPD, thickness of the TiO2 layer could be controlled precisely by adjusting the reaction conditions, therefore after removal of the template, the resulting material has a fibrous structure, mimicking the cellulose fibers shape. CdS nanoparticles were synthesized by thermochemical growth method and attached to TiO2 fibers through impregnation method. The pure composite nanofibers were...
Preparation of nanostructured and nanosheets of MoS2 oxide using oxidation method
, Article Ultrasonics Sonochemistry ; Volume 39 , 2017 , Pages 188-196 ; 13504177 (ISSN) ; Ramazani S. A. A ; Faghihi, M ; Fattahpour, S ; Sharif University of Technology
Abstract
Molybdenum disulfide (MoS2), a two-dimensional transition metal has a 2D layered structure and has recently attracted attention due to its novel catalytic properties. In this study, MoS2 has been successfully intercalated using chemical and physical intercalation techniques, while enhancing its surface properties. The final intercalated MoS2 is of many interests because of its low-dimensional and potential properties in in-situ catalysis. In this research, we report different methods to intercalate the layers of MoS2 successfully using acid-treatment, ultrasonication, oxidation and thermal shocking. The other goal of this study is to form S[dbnd]O bonds mainly because of expected enhanced...
Fabrication and characterization of graphene-based carbon hollow spheres for encapsulation of organic corrosion inhibitors
, Article Chemical Engineering Journal ; Volume 352 , 2018 , Pages 909-922 ; 13858947 (ISSN) ; Ramazani, S. A. A ; Mahdavian, M ; Taheri, P ; Mol, J. M. C ; Sharif University of Technology
Elsevier B.V
2018
Abstract
In this work, we synthesized carbon hollow spheres (CHSs) using the silica templating method, encapsulated 2-mercaptobenzimidazole (MBI) inhibitor in the CHSs and evaluated their corrosion inhibition performance upon exposure of mild steel to a saline solution containing the released inhibitor. The effects of silica template surface modification on the CHS structure was evaluated, while the structure and morphology of the synthesized CHS was analyzed using field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), Raman spectroscopy and X-ray diffraction (XRD) spectroscopy. Furthermore, thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy...
Hydrolysis kinetics of lead silicate glass in acid solution
, Article Journal of Nuclear Materials ; Volume 389, Issue 3 , 2009 , Pages 427-431 ; 00223115 (ISSN) ; Sadrnezhaad, Kh ; Raisali, G ; Hamidi, A ; Sharif University of Technology
2009
Abstract
Hydrolysis kinetics of the lead silicate glass (LSG) with 40 mol% PbO in 0.5 N HNO3 aqueous acid solution was investigated. The surface morphology and the gel layer thickness were studied by scanning electron microscopy (SEM) micrographs. Energy dispersive X-ray spectroscopy (EDS) and inductively coupled plasma spectroscopy (ICP) were used to determine the composition of the gel layer and the aqueous solution, respectively. The silicon content of the dissolution products was determined by using weight-loss data and compositions of the gel layer and the solution. The kinetic parameters were determined using the shrinking-core-model (SCM) for rate controlling step. The activation energy...
Controlled electrophoretic deposition of electrochemically exfoliated graphene sheets on Ag nanowires network
, Article Micro and Nano Letters ; Volume 14, Issue 4 , 2019 , Pages 389-393 ; 17500443 (ISSN) ; Tajabadi, F ; Mardi, S ; Taghavinia, N ; Amiri Zarand, A ; Dabirian, A ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
Electrochemical exfoliation of graphite has recently attracted a big attention as a simple, fast and scalable method for the preparation of high quality graphene, but there are some drawbacks that hinder its application. Direct deposition is one of the most critical challenges that makes it difficult to deposit uniform, compact and large scale graphene thin films. This work develops a facile electrophoretic deposition route to fabricate exfoliated graphene (EG) film on Ag nanowires (NWs) networks with a controllable film thickness in nanometers scale. EG thin films are deposited with different applied potentials and times from an EG dispersion in N, N-dimethylformamide solvent. Since...
Electrochemical sensors based on functionalized carbon nanotubes modified with platinum nanoparticles for the detection of sulfide ions in aqueous media
, Article Journal of Chemical Sciences ; Volume 131, Issue 3 , 2019 ; 09743626 (ISSN) ; Dolati, A ; Salmani Rezaie , S ; Sharif University of Technology
Springer
2019
Abstract
Abstract : Vertically aligned carbon nanotube (CNT) arrays were synthesized by thermal chemical vapor deposition (CVD) on stainless steel substrates coated by cobalt nanoparticles as catalyst. Morphological and elemental analyses conducted by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) revealed that bamboo-like CNTs were blocked by Co nanoparticles at the tips. The fabricated nanotubes underwent functionalization by electrochemical oxidation in sulfuric acid, and the subsequent structural studies, as well as Fourier transform infrared (FTIR) spectroscopy confirmed that the tips of functionalized CNTs were opened while oxygenated functional groups were...
A novel and cost-effective method for fabrication of a durable superhydrophobic aluminum surface with self-cleaning properties
, Article Nanotechnology ; Volume 31, Issue 46 , 2020 ; Taghvaei, E ; Moosavi, A ; Sharif University of Technology
IOP Publishing Ltd
2020
Abstract
A hierarchical superhydrophobic surface is prepared via a two-step boiling water immersion process and anodization of the treated aluminum substrate in a novel hydrophobic electrolyte of aluminum nitrate and stearic acid mixture at room temperature. The immersion time in boiling water had a significant influence on the morphology and durability of the sample. A pseudoboehmite coating is created on the aluminum surface during the boiling process, as revealed by the field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared (FTIR) spectrophotometer results. The energy-dispersive x-ray spectroscopy analysis confirmed the formation of hydrophobic coating surface after...
Wettability alteration of calcite rock from gas- repellent to gas-wet using a fluorinated nanofluid: A surface analysis study
, Article Journal of Natural Gas Science and Engineering ; Volume 83 , 2020 ; Shafiei, Y ; Shayesteh, M ; Dehghan Monfared, A ; Ghazanfari, M. H ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Wettability alteration analysis form gas-repellent to gas-wet with the aid of chemical agents has been subjected of numerous studies. However, fundamental understanding of the effect of surface tension of liquid on repellency strength, the change in the intermolecular forces due to the adsorption of nanoparticles onto the rock surfaces, and exposure of treated rock in brine are not well discussed in the available literature. In this study, X-ray diffraction, Atomic Force Microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were applied to characterize the treated and fresh samples. Dynamic and static contact angle measurements were then combined with six methods...
Synthesis and characterization of mixed–metal oxide nanoparticles (cenio3, cezro4, cecao3) and application in adsorption and catalytic oxidation–decomposition of asphaltenes with different chemical structures
, Article Petroleum Chemistry ; Volume 60, Issue 7 , 2020 , Pages 731-743 ; Ayatollahi, S ; Bahadorikhalili, S ; Esmaeilpour, M ; Sharif University of Technology
Pleiades Publishing
2020
Abstract
Abstract: This study investigates the catalytic activity of mixed–metal oxide nanoparticles with different surface acidities on asphaltene adsorption followed by catalytic oxidation–decomposition. Three different types of mixed–metal oxide nanoparticles (CeNiO3, CeCaO3 and CeZrO4) were synthesized, and their size, structure, and acid properties were characterized by field–emission scanning electron microscopy (FE–SEM), energy-dispersive X-ray spectroscopy (EDX), the high–resolution transmission electron microscopy (HR-TEM), X-ray powder diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area measurement and ammonia temperature-programmed desorption (NH3–TPD). Asphaltenes were extracted...
Enhanced decolorization of rhodamine B solution through simultaneous photocatalysis and persulfate activation over Fe/C3N4 photocatalyst
, Article Chemical Engineering Research and Design ; Volume 153 , 2020 , Pages 709-720 ; Padervand, M ; Soltanieh, M ; Vossoughi, M ; Sharif University of Technology
Institution of Chemical Engineers
2020
Abstract
In this study, organic contaminant degradation was intensified by increasing the oxidative capacity of the reaction system through simultaneous photocatalysis and heterogeneous persulfate activation. Fe nanoparticles were served as a multifunctional modifier to enhance the photoactivity of graphitic carbon nitride (CN), by tuning optical properties as well as persulfate (PS) activation rate, by introducing a new activation pathway. The synthesized photocatalysts were characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-visible...
Magnetic hyperthermia behaviour of Co and reduced GO nanocomposites
, Article Micro and Nano Letters ; Volume 15, Issue 4 , April , 2020 , Pages 239-244 ; Sadrnezhaad, S. K ; Sharif University of Technology
Institution of Engineering and Technology
2020
Abstract
Co-precipitation of CoCl2.6H2O with graphene oxide (GO) and heating at 400°C for 4 h under hydrogen resulted in the construction of cobalt/ reduced GO (Co/rGO) nanocomposite utilisable in magnetic thermal therapy. Field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometry, thermogravimetric analysis/derivative thermogravimetry, and X-ray diffraction methods characterised the samples. Time-temperature curves of the samples containing 30, 50, 70, and 100 µg ml−1 Co/rGO nanoparticles (NPs) suspended in phosphate-buffered saline were determined at different specific heating rates. Magnetic-field response of...
Selective separation of Congo Red from a mixture of anionic and cationic dyes using magnetic-MOF: Experimental and DFT study
, Article Journal of Molecular Liquids ; Volume 318 , 2020 ; Ekramipooya, A ; Gholami, M. R ; Sharif University of Technology
Elsevier B.V
2020
Abstract
La-MOF-NH2@Fe3O4 (magnetic-MOF) was used as an efficient, ultrafast, and selective adsorbent for the separation of Congo Red (CR) with 92.02% removal after 2 min. The magnetic-MOF was identified by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) surface area, Zeta Potential analysis, analysis of the magnetic hysteresis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS). Kinetics, isotherms, the effect of pH, thermodynamic, and selectivity of CR adsorption were investigated. The results confirmed that the adsorption kinetics complied with the pseudo-second-order model. The...
Hydrothermal synthesis of aligned Hydroxyapatite nanorods with ultra-high crystallinity
, Article International Journal of Engineering, Transactions B: Applications ; Volume 21, Issue 2 , 2008 , Pages 109-116 ; 1728-144X (ISSN) ; Rahimipour, M. R ; Yazdani, B ; Sadrnezhaad, S. K ; Amin, M. H ; Sharif University of Technology
Materials and Energy Research Center
2008
Abstract
Hydroxyapatite nanorods aligned with ultrahigh crystallinity and high-yield were successfully synthesized through a hydrothermal approach. In this experiment, a new composition of cetyltrimethylammonium bromide ((CH 3(CH2)15N+(CH3) 3Br-) was designated as CTAP)/Ca(NO3) 2/ (NH4)2HPO4/NaOH and distilled water under hydrothermal condition, to synthesize single crystal HAp nanorods with diameter of 20 ± 10 nm and length of 80 ± 20 nm, was introduced. Crystal phases were determined by X-ray diffraction (XRD). Scanning electron microscope (SEM) was applied to investigate the morphology. The microstructure of the HAp products were further observed by transmission electron microscope (TEM) and high...
Synthesis of magnetic ions-doped QDs Synthesized Via a facial aqueous solution method for Optical/MR dual-modality imaging applications
, Article Journal of Fluorescence ; Volume 31, Issue 3 , 2021 , Pages 897-906 ; 10530509 (ISSN) ; Zare, H ; Shahedi, Z ; Fazaeli, Y ; Rahighi, R ; Sharif University of Technology
Springer
2021
Abstract
This research reports the preparation and examination of Cadmium Telluride (CdTe) Quantum Dots and doping CdTe QDs with Europium (Eu), Gadolinium (Gd), and Manganese (Mn) prepared in aqueous solution using TGA as a capping agent. Magnetic QDs (MQDs) are important agents for fluorescence (FL) /magnetic resonance (MR) dual-modal imaging due to their excellent optical and magnetic properties. Herein, the chemical bonds, structural, fluorescence, and magnetized properties of CdTe QDs and effect of Mn, Eu, and Gd ions doping on their properties were examined by X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTM), Energy-dispersive X-ray spectroscopy (EDX),...
Improving mechanical properties and biocompatibility of 3D printed PLA by the addition of PEG and titanium particles, using a novel incorporation method
, Article Bioprinting ; Volume 27 , 2022 ; 24058866 (ISSN) ; Gerashi, E ; Zohrevand, M ; Zarei, M ; Sayedain, S. S ; Alizadeh, R ; Labbaf, S ; Atari, M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Polylactic acid (PLA) scaffolds produced by the fused deposition modeling (FDM) method have biocompatibility, close Young's modulus to that of bone, and the ability to make complex shapes. However, PLA has some drawbacks like brittleness, inappropriate mechanical strength and hydrophobicity, and a low degradation rate. In this study, polyethylene glycol (PEG) (5 and 10 wt%) by solving method and titanium (Ti) particles (5 wt%) by two different methods were mixed with PLA to address the mentioned problems. Extruded filaments were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and fourier transform infrared (FTIR). Surface morphology of the produced filaments...
Synthesis-structure-performance correlation for poly-aniline-Me-C non-precious metal cathode based on mesoporous carbon catalysts for oxygen reduction reaction in low temperature fuel cells
, Article Renewable Energy ; Volume 77 , 2015 , Pages 558-570 ; 09601481 (ISSN) ; Samiee, L ; Fattahi, M ; Seifkordi, A. A ; Shoghi, F ; Maghsodi, A ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
In this work, attempt is made to development of active non-precious metal catalysts (NPMCs) for the oxygen reduction reaction in polymer electrolyte fuel cells (PEFCs) based on the heat treatment of poly-aniline/transition metal/carbon precursors. All the materials have been characterized by X-ray diffraction (XRD) small and wide angle, N2 adsorption-desorption isotherms, high-resolution transmission electron microscopy (TEM), Scanning electron microscope (SEM) and X-ray photo-electron spectroscopy (XPS). Moreover for electrochemical evaluation of samples, Rotating Disk electrode (RDE) technique and Fuel Cell test were employed. The results showed that onset potential for the optimized...
Stable and efficient CuO based photocathode through oxygen-rich composition and Au-Pd nanostructure incorporation for solar-hydrogen production
, Article ACS Applied Materials and Interfaces ; Volume 9, Issue 33 , 2017 , Pages 27596-27606 ; 19448244 (ISSN) ; Siavash Moakhar, R ; Chua, C. S ; Kushwaha, A ; Dalapati, G. K ; Sharif University of Technology
Abstract
Enhancing stability against photocorrosion and improving photocurrent response are the main challenges toward the development of cupric oxide (CuO) based photocathodes for solar-driven hydrogen production. In this paper, stable and efficient CuO-photocathodes have been developed using in situ materials engineering and through gold-palladium (Au-Pd) nanoparticles deposition on the CuO surface. The CuO photocathode exhibits a photocurrent generation of ∼3 mA/cm2 at 0 V v/s RHE. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis and X-ray spectroscopy (XPS) confirm the formation of oxygen-rich (O-rich) CuO film which demonstrates a highly stable photocathode with retained...
An imprinted interpenetrating polymer network for microextraction in packed syringe of carbamazepine
, Article Journal of Chromatography A ; Volume 1491 , 2017 , Pages 1-8 ; 00219673 (ISSN) ; Bagheri, H ; Es haghi, A ; Amini Tabrizi, R ; Sharif University of Technology
Abstract
An imprinted interpenetrating polymer network (IPN) was synthesized and used as a medium for isolation of carbamazepine from urine samples. The polymer network consisted of a homogeneous polystyrene–sol gel hybrid constructed by in–situ radical polymerization method. In this process, within the sol–gel reaction duration, styrene monomer could penetrate into the reaction mixture and after the polymerization initiation, a monolithic IPN structure was prepared. The scanning electron microscopy (SEM) image and energy dispersive spectroscopy (EDX) are indications of the polystyrene dispersion at nano- to micro-meter level in the sol gel matrix. Eventually, the synthesized IPN was used as a...