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Improving the multi-step fabrication approach of copper nanofiber networks based transparent electrode for achieving superb conductivity and transparency
, Article Materials Research Express ; Volume 6, Issue 9 , 2019 ; 20531591 (ISSN) ; Angizi, S ; Sadrnezhaad, S. K ; Nikzad, M. J ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
Transparent Conductive Electrode (TCE), as an essential part of the optoelectronic devices, has become popular owing to its unique properties such as high optical transmittance and conductivity. Among utilized materials for fabrication of TCE, copper nanofibers (NFs)-network have been attracting much attention due to its extraordinary properties such as low sheet resistance, the scalable manufacturing and low-cost fabrication method. However, many challenges exist in the way of multi-step fabrication of network to increase the NFs continuity and consequently, improvement of their electrical conductivity as TCE. Herein, we report a deep investigation of the effective parameters on diameter...
A stable and high-energy hybrid supercapacitor using porous Cu2O-Cu1.8S nanowire arrays
, Article Journal of Materials Chemistry A ; Volume 8, Issue 4 , 2020 , Pages 1920-1928 ; Qorbani, M ; Shown, I ; Ojaghi Dogahe, B ; Sharif University of Technology
Royal Society of Chemistry
2020
Abstract
A three-dimensional electrode based on porous Cu2O-Cu1.8S nanowires is prepared by means of a facile fabrication process. In this electrode, nanowires are decorated with Cu1.8S polyhedral nanostructures on the top, which are directly grown on a copper foam, thereby eliminating the need for a polymer binder. As an electrochemical electrode, it exhibits an extrinsic pseudocapacitive charge storage mechanism, which is different from that of battery-like Cu2O-CuO and Cu(OH)2 electrodes. The areal and volumetric capacitances of the Cu2O-Cu1.8S electrode can reach 2.6 F cm-2 and ∼200 F cm-3, respectively, at 2 mA cm-2, which are much higher than those obtained using copper(i, ii) oxide and...
Novel magnetic flowable electrode for redox flow batteries: A polysulfide/iodide case study
, Article Industrial and Engineering Chemistry Research ; Volume 60, Issue 2 , 2021 , Pages 824-841 ; 08885885 (ISSN) ; Molaei Dehkordi, A ; Gharibi, H ; Roberts, E. P. L ; Sharif University of Technology
American Chemical Society
2021
Abstract
A novel approach named a magnetic flowable electrode (MFE) is proposed for the first time to enable enhancement of redox flow batteries (RFBs) performance. This approach enables the formation of a high active surface area electrode from magnetic nanomaterials, without the need to fabricate a self-supporting three-dimensional electrode structure. To form a simple MFE, magnetic modified carbon nanotubes are dispersed in the electrolyte, and permanent magnets are embedded behind the current feeder to apply a magnetic field across the flow cell channels. With circulating electrolyte, magnetic carbon nanotubes are aggregated on the graphite bipolar plate to form a well-structured nanoscale...
Urchin-like hierarchical ruthenium cobalt oxide nanosheets on Ti3C2T: XMXene as a binder-free bifunctional electrode for overall water splitting and supercapacitors
, Article Nanoscale ; Volume 14, Issue 4 , 2022 , Pages 1347-1362 ; 20403364 (ISSN) ; Esfandiar, A ; Mehdipour, H ; Sharif University of Technology
Royal Society of Chemistry
2022
Abstract
Synthesizing efficient electrode materials for water splitting and supercapacitors is essential for developing clean electrochemical energy conversion/storage devices. In the present work, we report the construction of a ruthenium cobalt oxide (RuCo2O4)/Ti3C2Tx MXene hybrid by electrophoretic deposition of Ti3C2Tx MXene on nickel foam (NF) followed by RuCo2O4 nanostructure growth through an electrodeposition process. Owing to the strong interactions between RuCo2O4 and Ti3C2Tx sheets, which are verified by density functional theory (DFT)-based simulations, RuCo2O4/Ti3C2Tx MXene@NF can serve as a bifunctional electrode for both water splitting and supercapacitor applications. This electrode...
Electrochemical determinations of 6-mercaptopurine on the surface of a carbon nanotube-paste electrode modified with a cobalt salophen complex
, Article Journal of Solid State Electrochemistry ; Volume 16, Issue 4 , April , 2012 , Pages 1643-1650 ; 14328488 (ISSN) ; Ghorbani Bidkorbeh, F ; Mohammadi, A ; Dinarvand, R ; Sharif University of Technology
2012
Abstract
A mixture of multi-walled carbon nanotube/graphite paste electrode modified with a salophen complex of cobalt was prepared and was applied for the study of the electrochemical behavior of 6-mercaptopurine (MP) using cyclic and differential pulse voltammetry (DPV). An excellent electrocatalytic activity toward the oxidation of MP was achieved, which led to a considerable lowering in the anodic overpotential and remarkable increase in the response sensitivity in comparison with unmodified electrode. Utilizing DPV method, a linear dynamic range of 1-100 μM with detection limit of 0.1 μM was obtained in phosphate buffer of pH 3.0. The electrochemical detection system was very stable, and the...
Voltammetric Determination of Tryptophan and 5-Hydroxytryptophan Using Graphite Electrode Modified with a Thin Film of Graphite/Diamond Nano-mixture And Determination of omeprazole Using Graphite Electrode
,
M.Sc. Thesis
Sharif University of Technology
;
Shahrokhian, Saeed
(Supervisor)
Abstract
At the first part of this thesis, a pyrolitic graphite electrode (PGE) modified with graphite/nanodiamond film (GND) was applied as a sensitive electrochemical sensor for determination and study of electrochemical behavior of tryptophan (Trp) and 5-hydroxytryptophan (5-HTP) in aqueous solutions. The results showed that GND caused a remarkable increase in the peak currents so the GND/PGE electrode surface was more sensitive to the concentration of Trp and 5-HTP than the PGE surface. The determination of Trp and 5-HTP were investigated by stripping voltammetry. Experimental parameters such as scan rate, pH, accumulation conditions and amount of the modifier used on the PGE surface were...
Optimized Pt Coating for High Charge Transfer- High Transparency Cathodes of Dye Sensitized Solar Cell
, M.Sc. Thesis Sharif University of Technology ; Taghavinia, Nima (Supervisor)
Abstract
Counter electrode of dye sensitized solar cell is prepared by deposition of a thin catalytic layer onto a conducting substrate and is responsible for reduction of iodide/triiodide redox electrolyte. Conventionally, counter electrode is made of platinum.
Depending on the method of deposition, the thickness of Pt layer varies. The Pt layer may be so thick that it acts as reflector and returns the incident light back to the cell. In this case, large amount of Pt is used and a rise in cost is been made, but only the Pt particles in the interface of counter electrode/electrolyte take part in the reduction reaction.
The aim of this project is optimization of making a counter electrode,...
Depending on the method of deposition, the thickness of Pt layer varies. The Pt layer may be so thick that it acts as reflector and returns the incident light back to the cell. In this case, large amount of Pt is used and a rise in cost is been made, but only the Pt particles in the interface of counter electrode/electrolyte take part in the reduction reaction.
The aim of this project is optimization of making a counter electrode,...
Fabrication of Composite Electrode Materials Based on Bi-Metalic Metal-Organic Frameworks for Designation of Amperometric Non-Enzymatic Glucose Sensors
, M.Sc. Thesis Sharif University of Technology ; Shahrokhian, Saeed (Supervisor)
Abstract
In the present study, the method of direct growth was used to grew bi-metalic MOFs based on cobalt and zinc, as electroactive centers, for preparing electrochemical sensors for the determination of glucose. In comparison to most of the electrochemical sensing platforms based on MOFs for determining glucose, which suffer from some disadvantages like time-consuming synthesis procedures and using hazardous organic solvents, the proposed in-situ growth method is much faster and without any need to toxic organic solvents. Herein, cobalt and zinc-based MOFs were grown on the surface of glassy carbon electrode by the direct and rapid conversion of layered double hydroxide nanosheets intermediates....
Adsorption Processes in Capacitive Deionization
, M.Sc. Thesis Sharif University of Technology ; Taghavinia, Nima (Supervisor)
Abstract
Today the water crisis affects billions around the world.According to existance of large amount of salty water on the earth, it seems one of the best soloution is desalination of salty water.There are methods for removing ions from water such as thermal methods, membrane methods , chemical methods and capacitive deionization.Capacitive deionization is based on the deviation of ions in the electric field.CDI system contains of two conductive porous electrodes that an elecric field is applied between them.While the brine pass through the space between the elecrodes the ions are absorbed by elecrodes. After a while the electrodes get saturated so a reverse potential is needed to regenerate the...
Investigation of Pb/PbS a positive Schottky junction formed on conductive glass in contact with alkaline solution
, Article Journal of Applied Physics ; Vol. 116, issue. 3 , July , 2014 ; ISSN: 00218979 ; Jafarian, M ; Gobal, F ; Mahjani, M. G ; Miandari, S ; Sharif University of Technology
Abstract
PbS on Pb thin film (Pb/PbS) was deposited on conductive glass (CG) substrate (CG/Pb/PbS) using electrochemical techniques to investigate the Schottky junction in solution. The CG/Pb/PbS electrode was investigated by different techniques based on thermionic emission theory. Electrochemical cell consisted of the CG/Pb/PbS as a working electrode in an alkaline solution showed character of the Schottky junction. Reduction and oxidation of H2O on the CG/Pb/PbS electrode were enhanced under illumination. Water photo splitting is the main process. Study of linear sweep voltammetry at around open circuit potential (OCP) allowed proposing a model based on the Schottky junction which is charged at...
Design, construction, and installation of movable electrode biasing system on tokamak
, Article Journal of Fusion Energy ; Volume 29, Issue 5 , 2010 , Pages 467-470 ; 01640313 (ISSN) ; Salar Elahi, A ; Tajdidzadeh, M ; Mohammadi, S ; Arvin, R ; Gheydi, M ; Abbaspour Tehrani Fard, A ; Sharif University of Technology
Springer New York LLC
Abstract
The first results of the movable electrode biasing experiments performed on the IR-T1 tokamak are presented. For this purpose, a movable electrode biasing system was designed, constructed, and installed on the IR-T1 tokamak, and then the positive voltage applied to an electrode inserted inside the tokamak limiter and the plasma current, poloidal and radial components of the magnetic fields, loop voltage, and diamagnetic flux in the absence and presence of the biased electrode were measured. Results compared and discussed
Electrocoagulation for COD and diesel removal from oily wastewater
, Article International Journal of Environmental Science and Technology ; Volume 13, Issue 1 , 2016 , Pages 231-242 ; 17351472 (ISSN) ; Azadi Aghdam, M ; Kariminia, H. R ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
Abstract
This study investigated the diesel and COD removal from oily wastewater by electrocoagulation. Experiments were conducted in a 2-l reactor using aluminum and iron electrodes. Effects of different parameters including pH (3–11), time (10–60 min), voltage (4.5–10.5 V), supporting electrolyte (NaCl concentration), electrode material and initial diesel concentration (3500–11,000 mg/L) were studied in order to evaluate the efficiency of electrocoagulation. Furthermore, the consumption of energy and the amount of sludge produced by this method were evaluated. The highest removal efficiency (COD removal of 99.1 ± 0.2 % and diesel removal of 98.8 ± 0.2 %) was observed under the following conditions:...
Smart chip for visual detection of bacteria using the electrochromic properties of polyaniline
, Article Analytical Chemistry ; Volume 91, Issue 23 , 2019 , Pages 14960-14966 ; 00032700 (ISSN) ; Farahmand Nejad, M. A ; Parolo, C ; Shahrokhian, S ; Merkoci, A ; Sharif University of Technology
American Chemical Society
2019
Abstract
Finding fast and reliable ways to detect pathogenic bacteria is crucial for addressing serious public health issues in clinical, environmental, and food settings. Here, we present a novel assay based on the conversion of an electrochemical signal into a more convenient optical readout for the visual detection of Escherichia coli. Electropolymerizing polyaniline (PANI) on an indium tin oxide screen-printed electrode (ITO SPE), we achieved not only the desired electrochromic behavior but also a convenient way to modify the electrode surface with antibodies (taking advantage of the many amine groups of PANI). Applying a constant potential to the PANI-modified ITO SPE induces a change in their...
Cobalt salophen-modified carbon-paste electrode incorporating a cationic surfactant for simultaneous voltammetric detection of ascorbic acid and dopamine
, Article Sensors and Actuators, B: Chemical ; Volume 121, Issue 2 , 2007 , Pages 530-537 ; 09254005 (ISSN) ; Zare Mehrjardi, H. R ; Sharif University of Technology
2007
Abstract
A carbon-paste electrode (CPE) is modified by incorporating cobalt-5-nitrosalophen (CoNSal) and tetraoctylammonium bromide (TOAB). The mechanism of electrocatalytic oxidation of dopamine (DA) and ascorbic acid (AA) at the surface of the CoNSal-modified CPE containing various percents of TOAB is thoroughly investigated by cyclic and differential pulse voltammetry. In solutions of pH 5.0, in which all studies are performed, DA exists as the positively charged species whereas AA is mainly as the neutral form. Therefore, the favorable ionic interaction (electrostatic repulsion) between the cationic form of DA and the cationic surfactant (TOA+) caused increasing the overvoltage for DA and...
Simultaneous voltammetric detection of ascorbic acid and uric acid at a carbon-paste modified electrode incorporating thionine-nafion ion-pair as an electron mediator
, Article Electrochimica Acta ; Volume 51, Issue 13 , 2006 , Pages 2599-2606 ; 00134686 (ISSN) ; Ghalkhani, M ; Sharif University of Technology
2006
Abstract
The electrochemical behavior of ascorbic acid (AA) and uric acid (UA) at the surface of a carbon-paste electrode modified with incorporate thionine-nafion ion-paired was thoroughly investigated. The results show the presence of nafion inside the matrix of modified electrode, because of the effective ion-pairing and hydrophobic interactions, significantly enhances the stability of thionine as an electron mediator inside the modified electrode. A high reproducibility in voltammetric response to analyte species results because of this enhancement. The cyclic voltammetric studies using the prepared modified electrode show the best electrocatalytic property for the electro-oxidation of AA and...
Efficient bio-nano hybrid solar cells via purple membrane as sensitizer
, Article BioNanoScience ; Vol. 4, issue. 1 , 2014 , pp. 71-77 ; ISSN: 21911630 ; Molaeirad, A ; Mohamadpour, R ; Khayati, M ; Mehrvand, J ; Sharif University of Technology
Abstract
Bacteriorhodopsin is a heptahelical protein found in the purple membrane of Halobacterium salinarum. The performance of bacteriorhodopsin was evaluated as a sensitizer in dye-sensitized solar cells (DSSCs). Bacteriorhodopsin was efficiently immobilized on the titanium dioxide nanoparticles and then tested for its ability to convert solar radiation to electricity. The photovoltaic performance of DSSC based on the bacteriorhodopsin sensitizer has been examined. Under AM1.5 irradiation, a short-circuit current of 0.28 mA cm−2, open-circuit voltages of 0.51 V, fill factor of 0.62, and an overall energy conversion efficiency of 0.09 % are achieved employing platinum as a counter electrode. Carbon...
Construction of a modified carbon paste electrode based on TiO2 nanoparticles for the determination of gallic acid
, Article Journal of Solid State Electrochemistry ; Volume 17, Issue 1 , 2013 , Pages 157-165 ; 14328488 (ISSN) ; Nami Ana, S. F ; Hashemnia, S ; Hormozi Nezhad, M. R ; Sharif University of Technology
2013
Abstract
A modified carbon paste electrode was prepared by incorporating the TiO2 nanoparticles in the carbon paste matrix. The electrochemical behavior of gallic acid (GA) is investigated on the surface of the electrode using cyclic voltammetry and differential pulse voltammetry. The surface morphology of the prepared electrode was characterized using the scanning electron microscopy. The results indicate that the electrochemical response of GA is improved significantly at the modified electrode compared with the unmodified electrode. Furthermore, the capabilities of electron transfer on these two electrodes were also investigated by electrochemical impedance spectroscopy. Under the optimized...
Kinetic studies of glucose electrocatalytic oxidation on GC/Ni electrode
, Article International Journal of Chemical Kinetics ; Volume 44, Issue 11 , 2012 , Pages 712-721 ; 05388066 (ISSN) ; Jafarian, M ; Forouzandeh, F ; Gobal, F ; Sharif University of Technology
2012
Abstract
Nickel-modified glassy carbon electrode (GC/Ni) prepared by galvanostatic deposition was used for the electrocatalytic oxidation of glucose in alkaline solutions where different electrochemical methods were employed. In cyclic voltammetry studies, in the presence of glucose an increase in the peak current of the oxidation of nickel hydroxide is followed by a decrease in the corresponding cathodic current. This suggests that the oxidation of glucose is being catalyzed through mediated electron transfer across the nickel hydroxide layer comprising nickel ions of various valence states. Under the chronoamperometric regime, the reaction followed a Cottrellian behavior and the diffusion...
Gold electrode modified with self-assembled monolayer of cysteamine-functionalized mwcnt and its application in simultaneous determination of dopamine and uric acid
, Article Electroanalysis ; Volume 24, Issue 2 , February , 2012 , Pages 425-432 ; 10400397 (ISSN) ; Mahdavi Shakib, A ; Ghalkhani, M ; Saberi, R. S ; Sharif University of Technology
Abstract
The voltammetric behavior of dopamine (DA) and uric acid (UA) on a gold electrode modified with self-assembled monolayer (SAM) of cysteamine (CA) conjugated with functionalized multiwalled carbon nanotubes (MWCNTs) was investigated. The film modifier of functionalized SAM was characterized by means of scanning electron microscopy (SEM) and also, electrochemical impedance spectroscopy (EIS) using para-hydroquinone (PHQ) as a redox probe. For the binary mixture of DA and UA, the voltammetric signals of these two compounds can be well separated from each other, allowing simultaneous determination of DA and UA. The effect of various experimental parameters on the voltammetric responses of DA and...
Electrocatalytic Oxidation of 1-Propanol and 2-Propanol on Electro-active Films Derived from Ni II-(N,N′-bis(2-Hydroxy, 3-Methoxy Benzaldehyde)-1,2-Propandiimine) Modified Glassy Carbon Electrode
, Article Electrocatalysis ; Volume 2, Issue 3 , Volume 2, Issue 3 , 2011 , Pages 163-171 ; 18682529 (ISSN) ; Rashvand avei, M ; Gobal, F ; Rayati, S ; Mahjani, M. G ; Sharif University of Technology
Abstract
Complexes of Ni II-(N,N′-bis(2-hydroxy, 3-methoxy benzaldehyde)-1,2-propandiimine) can be electro-polymerized onto GC electrode in an alkaline solution to give an electro-active film strongly adhered on the electrode surface. In alkaline solution, this poly-(Ni II{sal-1,2-pn(3-OMe) 2})/GC film shows the typical voltammetric response of a surface-immobilized redox couple, as can be anticipated for the Ni 2+/Ni 3+ transitions into the film. In addition, the film exhibits a potent and persistent electro-catalytic activity towards the oxidation of 1- and 2-propanol. In CV studies, in the presence of these alcohols, poly-(Ni II{sal-1,2-pn(3-OMe) 2})/GC electrode shows a new oxidation peak for the...