Search for: electrochemical-impedance-spectroscopy
Total 165 records
The effect of heat treatment on properties of Ni–P–SiO2 nano-composite coating, Article Protection of Metals and Physical Chemistry of Surfaces ; Volume 52, Issue 3 , 2016 , Pages 492-499 ; 20702051 (ISSN) ; Afshar, A ; Sharif University of Technology
Maik Nauka Publishing / Springer SBM
In this study, the surface morphology of Ni–P–SiO2 composite coating was investigated by field emission scanning electron microscopy (FESEM). The amount of SiO2 in the coating was examined by energy dispersive analysis of X-ray (EDX) and the Corrosion behavior of coating was evaluated by electrochemical impedance spectroscopy (EIS) and polarization techniques, showing the corrosion resistance of Ni–P–SiO2 diminished after heat treatment. The results showed that in the coating with 12.5 g/L SiO2, the coating hardness enhanced from 453VH to 980 VH before and after heat treatment. Furthermore, the wear behavior of the coating was analyzed before and after heat treatment
Modified glassy carbon electrodes based on carbon nanostructures for ultrasensitive electrochemical determination of furazolidone, Article Materials Science and Engineering C ; Volume 61 , 2016 , Pages 842-850 ; 09284931 (ISSN) ; Naderi, L ; Ghalkhani, M ; Sharif University of Technology
The electrochemical behavior of Furazolidone (Fu) was investigated on the surface of the glassy carbon electrode modified with different carbon nanomaterials, including carbon nanotubes (CNTs), carbon nanoparticles (CNPs), nanodiamond-graphite (NDG), graphene oxide (GO), reduced graphene oxide (RGO) and RGO-CNT hybrids (various ratios) using linear sweep voltammetry (LSV). The results of voltammetric studies exhibited a considerable increase in the cathodic peak current of Fu at the RGO modified GCE, compared to other modified electrodes and also bare GCE. The surface morphology and nature of the RGO film was thoroughly characterized by scanning electron microscopy (SEM), atomic force...
PH-responsive nanostructured polyaniline capsules for self-healing corrosion protection: the influence of capsule concentration, Article Scientia Iranica ; Volume 24, Issue 6 , 2017 , Pages 3512-3520 ; 10263098 (ISSN) ; Ghorbani, M ; Shojaei, A ; Mol, J. M. C ; Terryn, H ; Gonzalez Garcia, Y ; Sharif University of Technology
Nanostructured hollow polyaniline (PANI) capsules are good candidates for encapsulation of corrosion inhibitors and pH-responsive release when incorporated into organic coatings. In previous studies, the corrosion protection performance of PANI capsules, containing organic inhibitor 2-Mercaptobenzothiazole (MBT), was demonstrated. The present work studies the influence of capsule concentrations (i.e., 0.3, 1, and 2 wt%) on the corrosion protection properties of the coating system. Anti-corrosion properties of different coatings were compared by means of Electrochemical Impedance Spectroscopy (EIS) and Scanning Vibrating Electrode Technique (SVET). MBT loaded PANI capsules in epoxy ester...
Spray pyrolysis deposition of ZnFe2O4/Fe2O3 composite thin films on hierarchical 3-D nanospikes for efficient photoelectrochemical oxidation of water, Article Journal of Physical Chemistry C ; Volume 121, Issue 34 , 2017 , Pages 18360-18368 ; 19327447 (ISSN) ; Hussain, S ; Waleed, A ; Tavakoli, M. M ; Yang, S ; Khawar Rauf, M ; Fan, Z ; Arif Nadeem, M ; Sharif University of Technology
In this work, we study the role of nanotextured ZnFe2O4/Fe2O3composite thin films fabricated by ultrasonic spray pyrolysis (USP) on the photoelectrochemical water oxidation reactions. The ZnFe2O4/Fe2O3 composites with different molar ratios are deposited on three-dimensional nanospikes (NSP) substrate, and the results are compared with those for planar devices. It is observed that optical absorption and charge separation due to larger surface area is significantly enhanced in nanotextured photoactive ZnFe2O4/Fe2O3 films. After characterization of ZnFe2O4/Fe2O3 composite films with different molar ratios (ZF1, ZF2, and ZF3), we find that the nanotextured ZF1 composite with a molar ratio of...
Simultaneous electrodeposition of reduced graphene oxide/ag nanoparticles as a sensitive layer for voltammetric determination of tinidazole, Article Nano ; Volume 12, Issue 6 , 2017 ; 17932920 (ISSN) ; Navabi, M ; Mohammadi, R ; Sharif University of Technology
World Scientific Publishing Co. Pte Ltd 2017
A stable composite film of silver nanoparticles (Ag NPs) decorated on reduced graphene oxide is prepared by a two-step simple procedure. The surface morphology of the modified electrode is characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The electrochemical behavior of tinidazole (TNZ) on the surface of the modified electrode is investigated by linear sweep voltammetry and electrochemical impedance spectroscopy. The prepared composite electrode acts as a highly sensitive platform for the voltammetric determination of TNZ, leading to a significant increase in the reduction peak current of TNZ. The effects of experimental parameters such as the...
Corrosion behavior and microhardness of Ni-P-SiO2-Al2O3 nano-composite coatings on magnesium alloy, Article Journal of Materials Engineering and Performance ; Volume 26, Issue 5 , 2017 , Pages 2032-2039 ; 10599495 (ISSN) ; Rahemi Ardakani, S ; Rassaee, H ; Sharif University of Technology
Springer New York LLC 2017
In the present work, nano-composites of Ni-P-SiO2-Al2O3 were coated on AZ91HP magnesium alloy. The surface morphology of the nano-composite coating was studied by field emission scanning electron microscopy (FESEM). The amount of SiO2 in the coating was determined by energy-dispersive analysis of x-ray (EDX), and the crystalline structure of the coating was examined by x-ray diffractometer (XRD). All the experiments concerning the corrosion behavior of the coating carried out in 3.5 wt.% NaCl solution and evaluated by electrochemical impedance spectroscopy (EIS) and polarization technique. The results showed that an incorporation of SiO2 and Al2O3 in Ni-P coating at the SiO2 concentration of...
A high performance supercapacitor based on graphene/polypyrrole/Cu2O-Cu(OH)2 ternary nanocomposite coated on nickel foam, Article Journal of Physical Chemistry C ; Volume 121, Issue 12 , 2017 , Pages 6508-6519 ; 19327447 (ISSN) ; Shahrokhian, S ; Sharif University of Technology
A simple and low-cost electrochemical deposition method is used to prepare reduced graphene oxide/polypyrrole/Cu2O-Cu(OH)2 (RGO/PPy/Cu2O-Cu(OH)2) ternary nanocomposites as the electrode material for supercapacitor application. First, graphene oxide-polypyrrole (GO/PPy) nanocomposite is electrochemically synthesized on Ni foam by electro-oxidation of pyrrole monomer in an aqueous solution containing GO and Tiron. Subsequently, the GO/PPy film is converted to the corresponding reduced form (RGO/PPy) by an effective and eco-friendly electrochemical reduction method. Then, a thin layer of Cu2O-Cu(OH)2 is formed on RGO/PPy film by chronoamperometry. The RGO/PPy/Cu2O-Cu(OH)2 nanocomposite is...
Characterization of Ni-P-SiO2-Al2O3 nano-composite coatings on aluminum substrate, Article Materials Chemistry and Physics ; Volume 189 , 2017 , Pages 207-214 ; 02540584 (ISSN) ; Afshar, A ; Sadreddini, S ; Ghanbari, A. A ; Sharif University of Technology
Elsevier Ltd 2017
In the present work, nano-composites of Ni-P-SiO2-Al2O3 were coated on a 6061 aluminum substrate. The surface morphology of the nano-composite coating was studied by field emission scanning electron microscopy (FESEM). The amount of SiO2 in the coating was determined by Energy Dispersive Analysis of X-Ray (EDX) and the crystalline structure of the coating was examined by X-ray diffractometer (XRD). All the experiments concerning the corrosion behavior of the coating carried out in 3.5%wt NaCl solution and evaluated by electrochemical impedance spectroscopy (EIS) and polarization technique. The results showed that an incorporation of SiO2 and Al2O3 in Ni-P coating at the SiO2 concentration of...
Electrophoretic deposition of nano-zirconia coating on AZ91D magnesium alloy for bio-corrosion control purposes, Article Surface and Coatings Technology ; Volume 311 , 2017 , Pages 182-190 ; 02578972 (ISSN) ; Mohammadi, I ; Afshar, A ; Sharif University of Technology
Elsevier B.V 2017
Magnesium alloys are considered as potential biodegradable biomaterials in hard tissue implants. However, the fast degradation rate of these alloys in the biological environment causes failure of the implant just prior to the desirable time. In the present work, in order to decrease and curb the bio-corrosion rate of AZ91D Magnesium alloy, zirconia, which is classified as a biocompatible ceramic, was coated on the alloy surface through electrophoretic deposition (EPD) technique. The effects of alterations in the EPD parameters such as current density, duration time and ZrO2 particles concentration on coating properties including thickness, morphology and adhesion were then characterized....
Carbon based perovskite solar cells constructed by screen-printed components, Article Electrochimica Acta ; Volume 276 , 2018 , Pages 261-267 ; 00134686 (ISSN) ; Dracopoulos, V ; Mohammadi, M. R ; Lianos, P ; Sharif University of Technology
Elsevier Ltd 2018
Carbon based perovskite solar cells have been constructed by screen-printing three subsequent mesoporous layers of Titania, Zirconia and Carbon without a hole transporting layer and by infiltration of perovskite liquid precursor through the layers. Cell efficiency was optimized by varying the thickness of the three layers and the composition of the inks employed for screen printing. Electrochemical impedance spectroscopy was employed as a guide in the search for layer thickness optimization. All cell construction and testing was carried out under ambient conditions of 20–30% humidity. The cells were not encapsulated. The best cell gave an efficiency of 10.7%. All cells demonstrated a...
Ternary nanostructures of Cr2O3/graphene oxide/conducting polymers for supercapacitor application, Article Journal of Electroanalytical Chemistry ; Volume 823 , 2018 , Pages 505-516 ; 15726657 (ISSN) ; Shahrokhian, S ; Iraji Zad, A ; Sharif University of Technology
In this work, nanostructured composites of Cr2O3-graphene oxide (Cr2O3/GO) with conducting polymers; polyaniline (PANI) and polypyrrole (PPy) with the shape of cauliflower were synthesized via s simple and low cost one-step chronoamperometry method. The structures and morphologies of the resulting ternary nanocomposites were characterized by using Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The electrochemical capacitive properties of the prepared nanocomposites were evaluated by using cycle voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The...
Ultrasensitive detection of cancer biomarkers using conducting polymer/electrochemically reduced graphene oxide-based biosensor: Application toward BRCA1 sensing, Article Sensors and Actuators, B: Chemical ; Volume 266 , 2018 , Pages 160-169 ; 09254005 (ISSN) ; Salimian, R ; Sharif University of Technology
Elsevier B.V 2018
Breast Cancer (BRCA) is the most common threat in women worldwide. Increasing death rate of diagnosed cases is the main leading cause of designing specific genosensors for BRCA − related cancer detection. In the present study, an ultrasensitive label − free electrochemical DNA (E − DNA) sensor based on conducting polymer/reduced graphene − oxide platform has been developed for the detection of BRCA1 gene. An electrochemical method was applied as a simple and controllable technique for the electrochemical reduction of graphene oxide and also, electro − polymerization of pyrrole − 3 − carboxylic acid monomer. The results of the present work show that the polymer − coated reduced graphene −...
An efficient two-step approach for improvement of graphene aerogel characteristics in preparation of supercapacitor electrodes, Article Journal of Energy Storage ; Volume 17 , 2018 , Pages 465-473 ; 2352152X (ISSN) ; Shahrokhian, S ; zad, A. I ; Asadian, E ; Hosseini, H ; Sharif University of Technology
Elsevier Ltd 2018
We fabricated a high rate capability supercapacitor based on fluorine-doped graphene-carbon nanotubes aerogel network (G-CNT-F). Based on the electrochemical impedance spectroscopy data, the fluorination decreases the charge transfer resistance of graphene sheets, while CNTs act as spacer in the 3D structure. Therefore, both treatments improved the electrochemical properties of the resulted aerogel. Based on the Fourier transform infrared spectroscopy and XPS results, these excellent performances are attributed to semi-ionic bonds between fluorine and carbon. The specific capacitance of the graphene aerogel showed 78% decrease, when discharge current increases from 2 to 40 mA, while the...
Investigation on gel polymer electrolyte-based dye-sensitized solar cells using carbon nanotube, Article Ionics ; May , 2018 , Pages 1-7 ; 09477047 (ISSN) ; Khanmirzaei, M. H ; Lu, S. C ; Ramesh, S ; Ramesh, K ; Sharif University of Technology
Institute for Ionics 2018
A new poly (acrylonitrile) (PAN)-based gel polymer electrolyte (GPE) is fabricated to study the effect of carbon nanotube (CNT) on dye-sensitized solar cell (DSSC) efficiency. The GPEs are examined using electrochemical impedance spectroscopy (EIS) to analyze ionic conductivity. A maximum of 4.45 mS cm−1 ionic conductivity is achieved at room temperature with incorporation of 11 wt.% CNT. Performance of DSSC is examined with a solar simulator, and the highest energy conversion efficiency of 8.87% is achieved with the addition of 11 wt.% CNT. All GPE samples are found to follow Arrhenius model with temperature-dependent ionic conductivity testing. Structural properties are also characterized...
Band-gap narrowing and electrochemical properties in N-doped and reduced anodic TiO2 nanotube arrays, Article Electrochimica Acta ; Volume 270 , 2018 , Pages 245-255 ; 00134686 (ISSN) ; Khameneh Asl, S ; Mohammadpour, R ; Khameneh Asl, S ; Sharif University of Technology
Elsevier Ltd 2018
Electrochemical activity of TiO2 nanotube arrays (NTAs) is restricted by a wide band gap of TiO2. To overcome this restriction, we considered systematic research on two effective methods of doping of TiO2 NTAs such as the N-doping and electrochemical reductive doping and predicting the proper application of them. Band gap narrowing was occurred from 3.16 eV for undoped TiO2 NTAs to 2.9 and 2.7 eV at N-doped and self-doped TiO2 ones respectively. The electrochemical responses of the TiO2 NTAs before and after doping were examined by cyclic Voltammetry (CV) curve. To understand the electrochemical behavior of the undoped and doped TiO2 NTAs, electrochemical impedance spectroscopy (EIS) was...
An ultrasensitive label free human papilloma virus DNA biosensor using gold nanotubes based on nanoporous polycarbonate in electrical alignment, Article Analytica Chimica Acta ; 2018 ; 00032670 (ISSN) ; Ghorbani, M ; Sasanpour, P ; Karimizefreh, A ; Sharif University of Technology
Elsevier B.V 2018
An impedimetric human papilloma virus (HPV) DNA biosensor based on gold nanotubes (AuNTs) in label free detection was materialized. The AuNTs decorated nanoporous polycarbonate (AuNTs-PC) template as biosensor electrode was fabricated by electrodeposition method. The single strand DNA (ss-DNA) probe was covalently immobilized onto the AuNTs-PC electrode. The hybridization of target sequences with the ss-DNA probe was observed by the electrochemical impedance spectroscopy (EIS). The biosensor showed high selectivity and could differentiate between the complementary, mismatch and non-complementary DNA sequences. The EIS measurements were matched to Randle's equivalent circuit. The...
Formation of Zn-Ca-Ni tri cation's phosphate coating on steel and study that properties, Article TMS 2009 - 138th Annual Meeting and Exhibition, San Francisco, CA, 15 February 2009 through 19 February 2009 ; Volume 1 , 2009 , Pages 615-623 ; 9780873397384 (ISBN) ; Afshar, A ; Sharif University of Technology
A new Zinc phosphating bath, which produces coatings at relatively lower temperatures within a reasonable time by using of chemical accelerators has been devised. Improvement of the bath performance by the addition of divalent cations like calcium, nickel has been studied. Bath formulation and operating conditions have been optimized by coating weight determinations. Stable samples of phosphating formulations with and without calcium and nickel salts were prepared and the structure and morphology of the phosphate coatings were determined by using X-ray diffraction (XRD) techniques, scanning electron microscopy. ASTMB117 salt spray test and electrochemical impedance spectroscopy (EIS) were...
Electrodeposition of Ni-WndashB nanocomposite from tartrate electrolyte as alternative to chromium plating, Article Surface Engineering ; Volume 25, Issue 5 , 2009 , Pages 382-388 ; 02670844 (ISSN) ; Abdolmaleki, M ; Seyed Sadjadi, S. A ; Raghibi Boroujeni, M ; Arshadi, M. R ; Khoshvaght, H ; Sharif University of Technology
The effect of the bath chemistry and operating conditions on the chemical composition, microstructure and properties of NiWmdashB alloys deposited from tartrate baths on working electrode was studied for the first time by the pulsed current method. The investigations included the measurement of the current efficiencies and determination of the tungsten content in the electrodeposits. UV spectrometry was used for characterisation of complex formation. The grain size of deposits was determined by XRD. Also, the morphology of the deposits was studied by SEM. Amorphous NimdashWB alloys were successfully obtained by electrodeposition from the tartrate bath. The corrosion behaviour of NiWmdashB...
Synthesis and characterization of photocatalytically active crumpled-shape nanocomposites of nitrogen and sulfur co-doped ZnO–CeO2, Article Solar Energy Materials and Solar Cells ; Volume 203 , 2019 ; 09270248 (ISSN) ; Sabour Rouh Aghdam, A ; Nazari, M ; Bayat, A ; Saievar Iranizad, E ; Najafi Liavali, M ; Sharif University of Technology
Elsevier B.V 2019
In this study, crumpled-shape nanocomposite of nitrogen and sulfur co-doped ZnO–CeO2 (NSZC) was deposited on FTO substrate using one-step ultrasonic spray pyrolysis. Zinc acetate, cerium nitrate, and thiourea were dissolved in deionized water and used as starting solution. The samples were characterized using FESEM, XRD, UV–vis spectroscopy, EIS, and PL. The as-prepared nitrogen and sulfur co-doped ZnO–CeO2 nanocomposites were evaluated as high photocatalysts for degradation of methyl orange. Nearly 100% photocatalytic degradation of methyl orange was achieved for 180 min. The photoluminescence and electrochemical impedance spectroscopy revealed that co-doping of nitrogen and sulfur could...
Designing highly stable yet efficient solar cells based on a new triple-cation quasi-2D/3D hybrid perovskites family, Article Ceramics International ; Volume 45, Issue 16 , 2019 , Pages 20788-20795 ; 02728842 (ISSN) ; Abdizadeh, H ; Mirhosseini, M ; Taghavinia, N ; Sharif University of Technology
Elsevier Ltd 2019
In a nutshell, this study outlines the efficacy of mixed dimensional (2D/3D) hybrid perovskites by developing a new class of triple-cation quasi-2D perovskites having (S0.97S′0.03)2[Cs0.05(FA0.97MA0.03)0.95]n-1Pbn(I0.07Br0.03)3n+1 general composition, in which a mixture of ý5-ammonium valeric acid ýiodideý (S) and tetra-n-octylammonium ýbromide (S′) was employed ýas a spacer.ý The effect of the 2D and 3D structures molar ratios (i.e., C=2D/2D+3D) in the range of 0-100 % on photovoltaic performance of the deposited photoanodes was systemically studied. Drawing a comparison between such compounds and an analogous triple-cation 3D counterpart (i.e., Cs0.05(FA0.83MA0.17)0.95Pb(I0.83Br0.17)3) as...