Loading...
Search for:
electrochemical-oxidation
0.006 seconds
Total 29 records
An experimental and computational study on the rate constant of electrochemically generated N-acetyl-p- quinoneimine with dimethylamine
, Article International Journal of Electrochemical Science ; Volume 3, Issue 10 , 2008 , Pages 1092-1107 ; 14523981 (ISSN) ; Haqgu, M ; Nematollahi, D ; Gholami, R. M ; Sharif University of Technology
2008
Abstract
Electrochemical oxidation of acetaminophen (N-acetyl-p-aminophenol) (1) has been studied in the presence of dimethylamine (2) as a nucleophile in aqueous solution, by means of cyclic voltammetry and controlled-potential coulometry. The results indicate the participation of electrochemically generated N-acetyl-p-quinoneimine (1a) in Michael reaction with dimethylamine (2). Based on ECE mechanism, the observed homogeneous rate constant (kobs) of the above mentioned reaction is estimated by comparing the experimental cyclic voltammograms with the digital simulated results. Further more; kinetics and mechanism of the reaction were studied with ab initio calculation, Monte Carlo and QM/MM...
Electrochemical degradation of clindamycin by anodic oxidation on SnO2-Sb coated titanium anodes
, Article Environmental Engineering and Management Journal ; Volume 17, Issue 2 , February , 2018 , Pages 343-355 ; 15829596 (ISSN) ; Davoudi, M ; Farzadkia, M ; Esrafili, A ; Dolati, A ; Sharif University of Technology
Gheorghe Asachi Technical University of Iasi, Romania
2018
Abstract
Degradation of Clindamycin phosphate (CMP) was studied in aqueous solutions by an anodic oxidation process under galvanostatic conditions. The electrolysis cell consisted of a Ti/SnO2-Sb anode, prepared by dip-coating technique, and a 316 stainless steel cathode, both of which had a surface area of 6 cm2. The effects of critical factors, including CMP concentration, current density, initial pH, and the supporting electrolyte were evaluated. The electrochemical oxidation of CMP was controlled by mass transport within the studied range. The kinetic analysis indicated that the degradation reactions followed pseudo-first-order equation. The rate of CMP decay, as well as that of COD removal,...
Synthesis of Aligned Carbon Nanotubes and Their Modification with Noble Metallic Nanoparticles as Organic Analytes Biosensors
, Ph.D. Dissertation Sharif University of Technology ; Afshar, Abdollah (Supervisor) ; Dolati, Abolghasem (Supervisor)
Abstract
An efficient method has been developed to synthesize well-aligned multi-walled carbon nanotubes (MWCNTs) on a conductive Ta substrate by chemical vapor deposition (CVD). By varying CVD parameters, aligned CNTs (A-MWCNTs) with diameter between 20-100 nm and length of some micrometers with bamboo-like shapes were produced. Free-standing MWCNTs arrays were functionalized and purified through electrochemical oxidation. Then in order to improve the performance, facile template-free electrochemical routes were developed for the shape-selective synthesis of less-common Au nanostructures, including flower, sphere, dendrite, sheet and rod on A-CNTs at room temperature. The results showed that the...
Investigation of Aligned Carbon Nanotubes Modified by Platinum Nanoparticles as Hydrogen Sulfide Sensor
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor) ; Ghorbani, Mohamad (Supervisor)
Abstract
The present research describes sensing behavior of modified aligned carbon nanotubes toward detection of hydrogen sulfide. Aligned carbon nanotubes were grown on etched stainless steel by thermal chemical vapor deposition. Obtained CNTs have curved closed tips and bamboo like structure. Purification of carbon nanotubes were performed by electrochemical oxidation of CNTs. Potential cycling was applied on grown CNTs in different acid solutions and 0.2 M sulfuric acid was chosen to oxidize the CNTs. Carboxylic functional groups were produced by electrochemical oxidation of CNTs and can be observed in FTIR studies. These groups enhanced the electrochemical properties of electrodes and may act as...
Removal of Non-biodegradable Contaminants from Colored Textile Wastewater Using Electro Oxidation Process
, M.Sc. Thesis Sharif University of Technology ; Borghei, Mehdi (Supervisor) ; Ghasemi, Shahnaz (Supervisor)
Abstract
In the present study, the electrochemical oxidation process was introduced as a green process for complete degradation and removal of non-biodegradable pollutants from aquatic environments and effluents of various industries without the need to use chemicals and toxins. Research stages include comprehensive preliminary studies in the field of electrochemistry and wastewater treatment, software design of electro-oxidation reactor using titanium mesh anode and stainless steel cathode mesh inside a body made of polypropylene, designed cell construction and then evaluation of device performance in polluting environment Are different. In software simulation using COMSOL MULTIPHYSICS software, it...
Electrochemical Desulfurization of Sample Oil
, Ph.D. Dissertation Sharif University of Technology ; Farhadi, Fatolla (Supervisor) ; Shahrokhi, Mohammad (Co-Supervisor)
Abstract
Since, presence of sulfur compounds in fuels leads to environmental pollution and deacrese of fuel quality, fuel desulfurization should be considered for enhancing the fuel charachteristics. Electrochemical desulfurization was recogonized as one of desulfurization techniques that uses anode and cathode in an electrolytic environment under mild temperature and pressure. In this research, electrochemical desulfurization of crude gas-oil has been studied over electrodes of copper and stainless steel in the presence of NaOH and sulfuric acid. In this research, the effects of operational prameters like stirring rate, temperature, applied potential, sodium hydroxide/sulfuric acid addition as...
Enhancing Biological Removal Yield of Microplastics Using Advanced Oxidation Processes (AOPs)
, M.Sc. Thesis Sharif University of Technology ; Ghasemian, Saloumeh (Supervisor) ; Yaghmaei, Soheila (Supervisor) ; Ghobadinejad, Zahra (Supervisor)
Abstract
Statistics show that plastic production in the world is increasing, with 335 million tonnes in 2016 reaching 367 million tonnes in 2020. Since the presence of plastics in the dimensions of micro and nano, especially in aquatic environments can have adverse effects on human health and other living organisms, it has raised major environmental concerns. Therefore, it is necessary to think of measures to remove them and develop efficient methods for eliminating and decomposing microplastics. Recently, the advanced oxidation processes have attracted much attention because of the ability to eliminate recalcitrant compounds. In this study, electrochemical techniques and Fenton-based techniques for...
Modification of well-aligned carbon nanotubes with dihexadecyl hydrogen phosphate: Application to highly sensitive nanomolar detection of simvastatin
, Article Journal of Applied Electrochemistry ; Volume 44, Issue 2 , February , 2014 , Pages 263-277 ; ISSN: 0021891X ; Afshar, A ; Dolati, A ; Ghalkhani, M ; Sharif University of Technology
Abstract
The first usage of dihexadecyl hydrogen phosphate (DHP)-modified highly oriented multi-walled carbon nanotube (MWCNTs) forests in a sensor configuration was developed to investigate the electrochemical oxidation and determination of simvastatin (SV) in pharmaceutical dosage forms. Synthesis of well-aligned MWCNTs on a conductive Ta substrate by catalytic vapor deposition technique using a common chemical, ethylenediamine, and without being plasma-aided was reported. The electrochemical behavior and oxidation of SV at the aligned MWCNTs/DHP/Ta electrode were discussed in detail through cyclic voltammetry and differential pulse voltammetry. This modified electrode showed considerably higher...
Electrochemical oxidative desulfurization for high sulfur content crude gas-oil
, Article Separation and Purification Technology ; Volume 248 , 2020 ; Shahrokhi, M ; Farhadi, F ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Presence of sulfur components in liquid fuels should be controlled due to environmental issues and process considerations. In order to decrease the level of sulfurous compounds in crude gas-oil with 5750 ppmw sulfur, electrochemical oxidative desulfurization has been investigated over electrodes of copper and stainless steel because of their easy operation and mild process conditions. In this research, the effects of stirring rate, temperature, applied potential, sodium hydroxide addition as electrolyte media and water volume have been examined on the sulfur removal efficiency. The results show that electrical conductivity of gas-oil sharply increases with addition of electrolyte up to 613...
Kinetic modeling and simulation study for a sequential electrochemical extractive crude diesel desulfurization
, Article Separation and Purification Technology ; Volume 278 , 2022 ; 13835866 (ISSN) ; Farhadi, F ; Shahrokhi, M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
To reduce the sulfur content of crude diesel, several sets of experiments have been conducted using electrochemical oxidative desulfurization technique using electrolyte of NaOH at different applied voltages. Due to impacts of operating parameters on desulfurization, kinetic study is pursued and it is found that the kinetic follows a second order reaction rate with a high accuracy. The reaction of desulfurization was modeled using COMSOL and followed by coupled electrochemical oxidation-extraction, while the extraction process was particularly performed using process simulator. The effects of different solvents on extraction performance were studied and dimethyl sulfoxide was selected for...
Kinetics Investigation of the Degradation of Environmental Pollutants by Electro-Fenton Processes Using Iron Vanadate Nanoparticles
, M.Sc. Thesis Sharif University of Technology ; Rahman Setayesh, Shahrbanoo (Supervisor)
Abstract
Nanocomposite FeVO4/CeO2 was synthesized by hydrothermal method and was applied for removal of methyl orange. This nanocomposite was characterized by SEM, FT-IR, XRD, BET methods. SEM images showed that FeVO4 nanorode decorated on CeO2 spherical particles. The results of XRD patterns confirmed the triclinic structure for Fe(III)vanadate and the cubic fluorite structure for cerium oxide. The surface area of FeVO4, CeO2 and FeVO4/CeO2 was determined by BET analysis which the results represented an increase in surface area in nanocomposite using cerium oxide as support. The electro-Fenton reaction was performed in undivided electrochemical reactor using stainless steel electrodes and the...
Electrochemical Degradation of Organic Pollutants in the Presence of Spinel Cobalt Ferrite Nanoparticles: Investigation of the Effective Parameters and Evaluation of Degradation Kinetics
, M.Sc. Thesis Sharif University of Technology ; Rahman Setayesh, Shahrbanoo (Supervisor)
Abstract
In this study, CoFe2O4/CuO nanocomposite was synthesized by hydrothermal method and utilized for removal of metronidazole in electro-Fenton process. Nanocomposite was characterized by FT-IR, XRD, FE-SEM, VSM and BET methods. The Results of XRD patterns confirmed the monoclinic structure formation for copper(Ⅱ) oxide and the spinel structure for CoFe2O4. The FE-SEM images displayed the formation of CuO nanosheets for copper(Ⅱ) oxide and the decoration of cobalt ferrite nanoparticles on the surface of CuO nanosheets. Measurement of the surface area of nanocatalysts using BET isotherm represented the high surface area for CuO nanosheets and the increase of surface area of nanocomposite in...
Zeolite encapsulated Ni(II)-Schiff-base complex: A novel size-selective electro-catalyst for the determination of the purity of stevioside
, Article Talanta ; Volume 108 , April , 2013 , Pages 19-29 ; 00399140 (ISSN) ; Jafarian, M ; Etezadi, S ; Gobal, F ; Khakali, M ; Rayati, S ; Ghasem Mahjani, M ; Sharif University of Technology
2013
Abstract
Ship-in-a-bottle complex of nickel(II) containing the ligand N,N′-bis(2,4-dihydroxyacetophenone)-2,2-dimethylpropandiimine (H 2{salnptn(4-OH)2}) has been synthesized in zeolite Y. The characteristics of the encapsulated complex are identified by the methods of EDX, SEM, XRD, FT-IR and cyclic voltammetry. A catalytic effect in the electrochemical oxidation of glucose, fructose and sucrose, and a blocking effect in stevioside oxidation are demonstrated on the Ni II{salnptn(4-OH)2}-Y/CPE. The effects of some parameters, such as potential scan rate and concentration of carbohydrates are investigated. The rate constants for the catalytic reaction (k′) of carbohydrates are also obtained. The...
Electrodeposition of various au nanostructures on aligned carbon nanotubes as highly sensitive nanoelectrode ensembles
, Article Journal of Materials Engineering and Performance ; Volume 24, Issue 5 , May , 2015 , Pages 2005-2015 ; 10599495 (ISSN) ; Afshar, A ; Dolati, A ; Sharif University of Technology
Springer New York LLC
2015
Abstract
An efficient method has been developed to synthesize well-aligned multi-walled carbon nanotubes (MWCNTs) on a conductive Ta substrate by chemical vapor deposition. Free-standing MWCNTs arrays were functionalized through electrochemical oxidation with the formation of hydroxyl and carboxyl functional groups. Facile template-free electrochemical routes were then developed for the shape-selective synthesis of less-common Au nanostructures, including flower, sphere, dendrite, rod, sheet, and cabbage onto the aligned MWCNTs at room temperature. Especially, among all the synthesis methods for Au nanocrystals, this is the first report using electrochemical technique to synthesize wide variety...
Electrochemical oxidation of saccharose on copper (hydr)oxide-modified electrode in alkaline media
, Article Cuihua Xuebao/Chinese Journal of Catalysis ; Volume 31, Issue 11 , 2010 , Pages 1351-1357 ; 02539837 (ISSN) ; Rashvand Avei, M ; Danaee, I ; Gobal, F ; Mahjani, M. G ; Sharif University of Technology
2010
Abstract
A stable copper (hydr)oxide-modified electrode was prepared in 0.5 mol/L NaOH solution by cyclic voltammetry in the range of -250 to 1000 mV. It can be used for electrochemical studies in the range of -250 to 1000 mV without interfering peaks because there is no oxidation of copper. During an anodic potential sweep, the electro-oxidation of saccharose on Cu occurred by the formation of CuIII and this reaction also occurred in the early stages of the reversed cycle until it is stopped by the negative potentials. A mechanism based on the electro-chemical generation of CuIII active sites and their subsequent consumption by saccharose was proposed, and the rate law and kinetic parameters were...
A preliminary study of the electro-oxidation of l-ascorbic acid on polycrystalline silver in alkaline solution
, Article Journal of Power Sources ; Volume 195, Issue 1 , 2010 , Pages 165-169 ; 03787753 (ISSN) ; Gobal, F ; Sharif University of Technology
2010
Abstract
Electrochemical oxidation of l-ascorbic acid on polycrystalline silver in alkaline aqueous solutions is studied by cyclic voltammetry (CV), chronoamperometry (CA) and impedance spectroscopy (IS). The anodic electro-oxidation starts at -500 mV versus SCE and shows continued anodic oxidation in the cathodic half cycle in the CV regime signifying slowly oxidizing adsorbates. Diffusion coefficient of ascorbate ion measured under both voltammetric regimes is around 1.4 × 10-5 cm2 s-1. Impedance spectroscopy measures the capacitances associated with double layer and adsorption around 50 μF cm-2 and 4 mF cm-2 as well as the adsorption and decomposition resistances (rates). © 2009 Elsevier B.V. All...
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
Abstract
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...
Nanotextured spikes of α-Fe2O3/NiFe2O4 composite for efficient photoelectrochemical oxidation of water
, Article Langmuir ; Volume 34, Issue 12 , 2018 , Pages 3555-3564 ; 07437463 (ISSN) ; Tavakoli, M. M ; Waleed, A ; Virk, U. S ; Yang, S ; Waseem, A ; Fan, Z ; Nadeem, M. A ; Sharif University of Technology
American Chemical Society
2018
Abstract
We demonstrate for the first time the application of p-NiFe2O4/n-Fe2O3 composite thin films as anode materials for light-assisted electrolysis of water. The p-NiFe2O4/n-Fe2O3 composite thin films were deposited on planar fluorinated tin oxide (FTO)-coated glass as well as on 3D array of nanospike (NSP) substrates. The effect of substrate (planar FTO and 3D-NSP) and percentage change of each component (i.e., NiFe2O4 and Fe2O3) of composite was studied on photoelectrochemical (PEC) water oxidation reaction. This work also includes the performance comparison of p-NiFe2O4/n-Fe2O3 composite (planar and NSP) devices with pure hematite for PEC water oxidation. Overall, the nanostructured...
Hydrogen bubble template fabricated nano-architecture quaternary dendritic sulfide as cathode and electro-etched carbon fiber paper as anode electrode for total novel binder-free asymmetric supercapacitors
, Article Journal of Alloys and Compounds ; Volume 811 , 2019 ; 09258388 (ISSN) ; Naderi, L ; Shahrokhian, S ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
A novel electrode consisting of 3D porous nickel‒cobalt‒copper sulfide dendritic structures is synthesized, in which, for the first time ternary Ni–Co–Cu foam is constructed through hydrogen bubble template and followed by sulfidization via a hydrothermal reaction in thiourea. The 3D, porous Ni–Co–Cu dendritic sulfide electrode exhibits a high specific capacitance of 1203.75 F g−1 (0.963 F cm−2) at current of 1.0 mA and excellent cycling stability, excellent ratability along with high cycle stability. An asymmetric supercapacitor (ASC) using dendritic sulfide structures and reduced electro-etched carbon fiber paper (RECF) as the positive and negative electrodes, respectively is developed....
Metal-organic framework derived NiSe2/CeO2nanocomposite as a high-performance electrocatalyst for oxygen evolution reaction (OER)
, Article Sustainable Energy and Fuels ; Volume 5, Issue 11 , 2021 , Pages 2994-3000 ; 23984902 (ISSN) ; Moravvej, S. H ; Moazzeni, M ; Akbarzadeh, E ; Sharif University of Technology
Royal Society of Chemistry
2021
Abstract
The development of efficient and cost-effective catalysts for the oxygen evolution reaction is highly desirable for applications that are based on sustainable and clean technologies. In this study, we report the synthesis of a series of cerium(iv) oxide and nickel diselenide nanocomposites (NiSe2/CeO2) as efficient electrocatalysts for the oxygen evolution reaction in an alkaline medium. The ratios of the two substances were optimized to reach the highest catalytic activity. The structure and morphology of synthesized materials were investigated by XRD, FE-SEM, EDX, BET, XPS, and TEM techniques. It was observed that the nanocomposite with a 10 : 1 mass ratio of NiSe2to CeO2showed the best...