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    Electrodeposition of Platinum Nanowires

    , M.Sc. Thesis Sharif University of Technology Hashemi Darian, Sahar (Author) ; Dolati, Abolghasem (Supervisor) ; Ghorbani, Mohammad (Supervisor)
    Platinum nanowires were prepared by electrodeposition in polycarbonate membrane, with different average diameter of nanowires about 15, 50 and 100 nm and the height about 6 µm. Kinetics of electrodeposition process were studied by electrochemical techniques such as voltammetry and chronoamperometry methods. Diffusion coefficient was then calculated from the electrochemical parameters and consequently the density of primer nuclei was extracted. The morphology of Pt nanowires was characterized by SEM, TEM and EDX. The results show that growing Nanowires on the surface of template is branch-like. The electro-oxidation of methanol and hydrogen on this electrode is investigated at room... 

    Wear-Resistant Nickel-Titanium Nitride Composite Coating by Electrochemical Method

    , M.Sc. Thesis Sharif University of Technology Parhizkar, Nafise (Author) ; Dolati, Abolghasem (Supervisor)
    Metal matrix nanocomposites contains ceramic ultrafine particles in a metal matrix, are used to improve the mechanical properties such as hardness and wear of coatings. For developing metal matrix nanocomposites, there are many methods. Electrochemical deposition process is one of these methods that have some advantages like uniform depositions on substrates with complex shapes, low cost, good repeatability and reducing waste. In this project, for increasing the hardness and wear resistance of nickel, composite coatings of nickel - titanium nitride was created by using electrochemical deposition of Watts bath contained titanium nitride particles. In order to increase the amount of... 

    Preparation and Study of Microstructural and Mechanical Properties of Ni-Tio2 Based Nanocomposite by Electrochemical Deposition Method

    , M.Sc. Thesis Sharif University of Technology Sariri, Farshid (Author) ; Mohammadi, Mohammad Reza (Supervisor) ; Ekrami, Ali Akbar (Co-Advisor)
    In the present work preparation of Ni-TiO2 films and their microstructural and mechanical properties were studied. For film preparation, DC current mode of electrochemical deposition method was used in Watts Nickel bath with different concentrations of transparent TiO2 sol up to 30 mL/L. It presents a new generation of nano Ni-TiO2 coating as a composite film for corrosion and erosion resistance applications. The best wear volume of 0.0046 mm3 was achieved for 30 mL/L Ni-TiO2 nanocomposite in comparison to 0.0071 mm3 for pure Ni film. Moreover, the coating hardness increased to ~345 HV50 for Ni-TiO2 nanocomposite. Corrosion rate of the coatings improved down to 1.10E-05 mm/year with addition... 

    Electrodeposition of Rhenium and Nickel Nanoparticles

    , M.Sc. Thesis Sharif University of Technology Ataee, Hamed (Author) ; Sadrnezhad, Khatiboleslam (Supervisor)
    In the last decade, a great deal of attention has been paid to the study of synthesis of Nanoparticles, because of the widespread use of this material in applications involving Fuel cells and magnetic devices. In this thesis, we report some interesting features in the electrodeposition of metallic nanoparticles. The electrochemical phase formation of rhenium and nickel on the surface of P-Si (100) substrate plus morphological, topographical and fractal aspects of the accumulated surface were investigated in this research by means of chronoamperometry method and by utilization of AFM and SEM. The nucleation and growth mechanisms on silicon electrode are characterized using cyclic voltammetry... 

    The Investigation on Hydroxyapatite Coating on Magnesium Alloy and Its Properties

    , M.Sc. Thesis Sharif University of Technology Mazaheri Kalahrood, Amir (Author) ; Afshar, Abdollah (Supervisor)
    Magnesium and its alloys are biodegradable materials with mechanical properties similar to the bone tissue, therefore these materials are suitable for producing orthopedic implants. Unfortunately Magnesium and its alloys are corroded too fast in physiological environment which is the main obstacle for usage of these materials as orthopedic implants. Producing Hydroxyapatite(HA) coatings on surface of Magnesium and its alloys is one of the popular and useful methods for reducing the corrosion rate in physiological environment. HA is a biocompatible and bioactive coating with the ability to bond chemically with the bone tissue and therefore it is largely used as a bioactive coating on the... 

    Nickel Nano Particles Pulse Electrodeposition

    , M.Sc. Thesis Sharif University of Technology Afsari, Maryam (Author) ; Dolati, Abolghasem (Supervisor)
    Syntheses of coats including nickel nano-particles by electrodeposition have been
    investigated for over 10 years. A method of testing according to surface reply was chosen
    to reveal the effect of each pulse parameters (including duty cycle, frequency, average
    current density, off time (toff) and on time (ton)) and the effect of saccharin concentration
    on electroplating cathode efficiency, nanostructure. Pulse electroplating test of nickel was
    composed by 30 tests. Pulse electroplating with relatively high peak current density was
    employed and saccharine was added to increase deposition and rate of nickel nucleation on
    surface. According to the results of cathode... 

    Electrodeposition of Ni-SiC Nanocomposite Coatings

    , Ph.D. Dissertation Sharif University of Technology Sohrabi Jahromi, Abouzar (Author) ; Dolati, Abolghasem (Supervisor) ; Ghorbani, Mohammad (Co-Advisor)
    In this project Ni-SiC nanocomposite coatings were electrodeposited using Watts nickel bath with addition of SiC particles to the bath. Optimization of Ni-SiC electrodeposition parameters was done using Response Surface Methodology (RSM). At specific conditions, 67 Vol% of 10nm SiC is incorporated in nickel electrodeposits which is unique and not yet reported. Study nanomechanical properties of these coatings using Nanoindentation method, it was realized that the dislocation density is increased as force increasing which is in agreement with increasing intensity of (220) and (200) reflections and intensity attenuation of (111) reflection. Nanoscratch tests show that these... 

    Electrodeposition of Cu/WC Nanocomposite

    , M.Sc. Thesis Sharif University of Technology Barmaki, Mohammad Reza (Author) ; Dolati, Abolghasem (Supervisor) ; Afshar, Abdollah (Supervisor)

    Solid-phase Microextraction of BTEXs by Sol-Gel-Based Trimethoxy Silyl Propyl Methacrylate Fiber

    , M.Sc. Thesis Sharif University of Technology Soltannezhad dizaji, Mahda (Author) ; Bagheri, Habib (Supervisor)
    Conventional solid phase microextraction fibers posses relatively low recommended operating temperature, instability and swelling in organic solvents, breakage of the fiber, stripping of coatings, and bending of the needle. Some of these problems have been obviated by covalent bonding of the polymer phase to the fused-silica substrate by sol-gel technology, but the easy breakage of the fiber still is a remaining challenge In this work, after successful fabrication of unbreakable SPME fibers based on 3-(trimethoxysilyl)propyl methacrylate precursor deposited on the surface of copper wire, the same approach was carried out to synthesis new sol-gel based SPME fibers. Three different coated... 

    Electrochemical Deposition of Zinc/Nickel Multilayer Coating and Investigating the Effect of Morphology and Phase Structure on the Dissolution of Zinc/Nickel Alloy Coating

    , M.Sc. Thesis Sharif University of Technology Tahmasebi, Maedeh (Author) ; Ghorbani, Mohammad (Supervisor)
    The multilayer coating (Zn-Ni)1/(Zn-Ni)2 is deposited from a single bath with a zincate-sulfate compound and by changing the current density. The effect of current density and the number of layers on the chemical composition, surface morphology, roughness, phase structure, and corrosion resistance of multilayer coatings respectively using atomic absorption spectroscopy, FE-SEM microscope, roughness tests, X-ray analysis, and electrochemical techniques such as Tafel polarization and impedance was investigated and compared with single-layer coatings. Because the amount of nickel in the composition of the coatings is less than 27%, in all the studied currents, the deposition is anomalous. The... 

    Iron‑vanadium oxysulfide nanostructures as novel electrode materials for supercapacitor applications

    , Article Journal of Electroanalytical Chemistry ; Volume 818 , 2018 , Pages 157-167 ; 15726657 (ISSN) Asen, P ; Shahrokhian, S ; Iraji Zad, Azam ; Sharif University of Technology
    Elsevier B.V  2018
    Iron‑vanadium oxysulfide (Fe-VO-S) nanostructures with different Fe:VO atomic ratios are synthesized by a facile and low cost electrochemical deposition method. The synthesis of the various samples is confirmed by the physicochemical characterizations such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM). For different Fe-VO-S nanostructures, the correlation between the physicochemical and the electrochemical properties is investigated. It is found that the Fe:VO atomic ratio has an important effect on the structure and size of the resulted particles.... 

    Room temperature selective sensing of aligned Ni nanowires using impedance spectroscopy

    , Article Materials Research Express ; Volume 7, Issue 2 , 24 February , 2020 Mohammadi, M ; Fardindoost, S ; Iraji Zad, A ; Almasi Kashi, M ; Sharif University of Technology
    Institute of Physics Publishing  2020
    Room temperature gas sensing behavior of arrayed one-dimensional (1D) nickel nanowires (Ni NWs) are investigated using impedance spectroscopy. Ni nanowires synthesized via electrochemical deposition method based on anodic aluminum oxide (AAO) templates. Their structural characterization verified by scanning electron microscopy (SEM), x-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) analysis. Impedance spectroscopy as an essential technique utilized to understand the mechanism of gas interaction with the wires through the changes in their electronic behavior. Bode and Nyquist plots with the real and imaginary impedances are plotted versus frequency range of 500 Hz... 

    Synthesis and properties of Fe-Pd Shape Memory thin Films by Electrodeposition

    , M.Sc. Thesis Sharif University of Technology Rezaei, Milad (Author) ; Ghorbani, Mohammad (Supervisor) ; Dolati, Abolghasem (Supervisor)
    In this study, an alkaline bath for co-deposition of Fe and Pd was selected. In order to investigate the mechanism of deposition, each of the metals iron and palladium electrodeposited from selected bath separately; and the kinetics of electrodeposition by electrochemical techniques such as linear voltammetry, cyclic voltammetry, chronoamperometry and chronopotentiometry were evaluated. Electrodeposition processes of Fe, Pd and their alloy were irreversible and under diffusion of reducing agents are controlled. Moreover the electroreduction of palladium from utilized bath was performed in two steps. At following, the mechanism of iron– palladium alloy electrocrystallization was discussed and... 

    Fabrication of Hybrid Supercapacitors Based on Graphene-Conducting Polymers and Some Metallic Oxides and Sulfides and Investigation of Their Electrochemical Behavior

    , Ph.D. Dissertation Sharif University of Technology Asen, Parvin (Author) ; Shahrokhian, Saeed (Supervisor) ; IrajiZad, Azam (Co-Supervisor)
    In this research, metal oxides and hydroxides with carbon materials and conductive polymers (CPs), as well as transition metal oxysulfide nanostructures (TMOS), hybrid of Tin oxide and sulfie and polyphasphate-reduced graphene oxide (PPO-RGO) have been used as an active electrode materials for supercapacitors. In the first section of thesis, Tiron and graphene oxide (GO) were used as an anionic dopants to increase the capacity and stability of polypyrrole (PPy). In order to increase the capacity of Tiron/PPy/GO nanocomposite, vanadium oxide (V2O5) was used. The Tiron/PPy/GO/V2O5 nanocomposite was deposited on a stainless steel (SS) as a substrate via one-step electrochemical deposition... 

    Fabrication and Characterization of Electrochemical Properties of Porous Ni and Ni/rGO Nanocomposite by Electrochemical Deposition for Pseudocapacitor Application

    , M.Sc. Thesis Sharif University of Technology Sabzeh, Parisa (Author) ; Abachi, Parvin (Supervisor) ; Dolati, Abolghasem (Supervisor)
    Fabrication of porous hybrid coatings, specially in combination with carbon compounds, can improve the electrochemical behavior of the coating. In this study, graphene oxide (GO) was first synthesized by tour method. After examining different methods to create a porous coating, the electrochemical coating method for simultaneous deposition of GO and nickel on the copper substrate was selected. CTAB was used to form nanometer porosity in the coating structure. In order to investigate the effect of GO on the properties of the deposited coating, two porous coatings of nickel (Ni) and nickel reduced-graphene oxide (Ni-rGO) were investigated by different analyzes. These analyzes include FESEM... 

    Investigation of Optical-Electrochemical Properties of Tungsten/Tungsten Trioxide Nanosheets with Layered Double Hydroxides Catalysts for Seawater Spilitting

    , M.Sc. Thesis Sharif University of Technology Zamani Faradenbeh, Zahra (Author) ; Simuchi, Abdolreza (Supervisor) ; Mushfeq, Alireza (Supervisor)
    Decomposition of seawater with the help of sunlight is one of the most promising ways to produce hydrogen as a clean and acceptable fuel in the future. Tungsten photoelectrode is a suitable option for seawater decomposition due to its medium bandwidth, excellent load transfer properties, good chemical stability in acidic and neutral environments, abundance and cost-effectiveness. On the other hand, intermediate metal catalysts (Fe, Ni, Co) are very important due to their abundance in the earth's crust and their stability in alkaline and neutral environments instead of oxides of precious metals (RuO2, IrO2). In this study, tungsten plate (WO3) nanostructures were grown on the surface of a... 

    Synthesis and characterization of electrochemically grown CdSe nanowires with enhanced photoconductivity

    , Article Journal of Materials Science: Materials in Electronics ; Volume 26, Issue 3 , March , 2015 , Pages 1395-1402 ; 09574522 (ISSN) Kalhori, H ; Irajizad, A ; Azarian, A ; Ashiri, R ; Sharif University of Technology
    Springer New York LLC  2015
    CdSe nanowires were grown in polycarbonate track etched membrane with pore diameter of 80 nm by an electrochemical deposition technique. The mechanism of the growth was studied during the potentiostatic deposition of nanowires. X-ray photoelectron spectroscopy and energy dispersive spectrometry results showed binding of fragments and fraction of atoms for the CdSe nanowires. Microstructure and morphology of synthesized CdSe nanowires were observed by scanning electron microscopy. Optical spectrophotometry technique was used to determine the energy band gap of CdSe nanowires. It was found that the nanowires were resistive in the dark and exhibited a pronounced visible light photoconductivity.... 

    One-step fabrication of electrochemically reduced graphene oxide/nickel oxide composite for binder-free supercapacitors

    , Article International Journal of Hydrogen Energy ; Volume 41, Issue 39 , 2016 , Pages 17496-17505 ; 03603199 (ISSN) Shahrokhian, S ; Mohammadi, R ; Asadian, E ; Sharif University of Technology
    Elsevier Ltd  2016
    A three-dimensional (3D) graphene/Nickel oxide (ERGO/NiO) composite electrode have been fabricated directly on a Nickel foam substrate via a one-step electrochemical co-deposition in an aqueous solution containing Nickel nitrate and GO. By using this simple and one-step electrochemical deposition, it is possible to produce binder-free composite electrodes with improved electrochemical properties using a low-cost, facile and scalable technique. It is observed from FE-SEM images that graphene oxide sheets affect the electrodeposition of nickel oxide. The optimized ErGO/NiO electrode developed in this work exhibits high charge storage capacity with a specific capacitance of 1715.5 F g−1 at... 

    Composites of reduced graphene oxide/nickel submicrorods for non-enzymatic electrochemical biosensing: application to amperometric glucose detection

    , Article Journal of the Electrochemical Society ; Volume 167, Issue 8 , 2020 Mohammadzadeh, A ; Mazaheri, M ; Sedighian, A ; Ghanbari, H ; Simchi, A ; Sharif University of Technology
    Institute of Physics Publishing  2020
    For the rapid detection of hyperglycemia in human blood, we adopted a facile and two-step electrochemical procedure to prepare nickel/reduced graphene oxide (rGO) hybrid electrodes in the framework of a three-dimensional (3D) nanostructure. High-density and vertically-aligned nickel submicrorods with an average diameter of 155 ± 15 nm and a length of 7 ± 1 μm (an aspect ratio of about 40-50) were prepared by template-mediated electrochemical deposition techniques. Networks of rGO nanosheets between the rod-shaped arrays were formed by the cathodic electrophoretic deposition method. The synergistic effect of nickel morphology (planar and high-density rod-shaped arrays) and graphene oxide... 

    Electrochemical deposition of flower-like nickel nanostructures on well-defined n-si(111):h

    , Article International Journal of Engineering, Transactions B: Applications ; Volume 21, Issue 2 , 2008 , Pages 177-182 ; 1728-144X (ISSN) Torabi, M ; Khalifehzadeh, R ; Arami, H ; Sadrnezhaad, S. K ; Sharif University of Technology
    Materials and Energy Research Center  2008
    In this paper the electrodeposition of nickel on n-Si(111):H substrate, in the presence of sulphuric acid, was studied. Cyclic voltammetry has been used to characterize the electrochemical behavior of the system. The nickel deposits had a flower-like morphology with the spherical nanostructure nucleus, distributed uniformly on the surfaces of the prepared n-Si(111) substrate