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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)
    Abstract
    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... 

    The Use of Non-platinum Electro-catalyst for Low Temperature Fuel Cells

    , M.Sc. Thesis Sharif University of Technology Hamzehie, Mohammad Ehsan (Author) ; Samiee, Leila (Supervisor) ; Seifkordi, Ali Akbar (Co-Advisor)
    Abstract
    In the recent decades, Polymer Electrolyte Membrane Fuel Cells (PEFC) have been known as an appropriate type of fuel cells, due to being electrochemical converter and clean energy generator with high power density and having low operation temperature and launch time. Palatine is one of the major materials that are used in electro-catalysts of fuel cell. Due to shortage of palatine resources and its high price, fuel cell production is not economical. To achieve economic conditions for production of fuel cell, two major methods are proposed:
    1) Reduction of the employed amount of palatine in electro-catalyst
    2) Full replacement of palatine with cheap materials
    In the current... 

    Comprehensive Study of an Ag@Pt Core–shell Nanoparticles Supported on Carbon Structure in a Proton Exchange Membrane Fuel Cell

    , Ph.D. Dissertation Sharif University of Technology Esfandiari, Ali (Author) ; Kazemeini, Mohammad (Supervisor) ; Bastani, Dariush (Supervisor)
    Abstract
    Core-shell structures of Ag@Pt nanoparticles (NPs) dispersed on Carbon Vulcan XC-72, Multiwalled carbon nanotube and reduced graphene oxide (rGO) support containing different Ag:Pt mass ratios and applied to the oxygen reduction reaction (ORR) in a proton exchange membrane fuel cell (PEMFC) were synthesized by the ultrasonic and reduction treatment method. The morphology of as-prepared catalysts characterized by the high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and induced coupled plasma atomic emission spectroscopy (ICP-OES). The ORR activities and stabilities of catalysts were studied through electrochemical measurements utilizing the Cyclic Voltammetry... 

    Enhancement of Water Splitting Efficiency of TiO2 Nanotube Arrays by Nanostructured Cobalt Oxide Electrocatalyst

    , M.Sc. Thesis Sharif University of Technology Qarechalloo, Shervin (Author) ; Naseri, Naimeh (Supervisor)
    Abstract
    The 21st century is facing two major obstacles on the way of accessing clean and renewable energies: first, the rapidly increasing need to the energy resources; and second, the limitations - as well as side-effects - of the conventional fossil fuels. Meanwhile, the production of the solar hydrogen, through water splitting, has been proposed as a promising solution to find a clean and effective source of energy. This process occurs in photo-electro-chemical systems with the activation energy that lies within the range of visible light. One approach that herewith comes to mind, is to start the process by utilizing semiconductors to absorb the sunlight. In order to overcome the overpotential... 

    Synthesis and Performance Evaluation of FeOOH Elechtrocatalyst Supported on Nickel Foam for Oxygen Evolution Reaction

    , M.Sc. Thesis Sharif University of Technology Nick Maleki, Ali (Author) ; Moshfegh, Alireza (Supervisor) ; Naseri, Naimeh (Co-Supervisor)
    Abstract
    Due to imminent shortage of fossil fuels, environmental issues that occur from their intensive use, population growth and industrialization of societies moving towards renewable energy sources is inevitable. Sun is the most clean and abundant source of energy but it is needed to be accompanied with an energy storage system as it is intermittent and cannot supply our required energies on demand. Water splitting electrochemical cells are promising solutions to cope with this problem by producing hydrogen as a clean fuel. The overpotential imposed by anode is the bottleneck of the water splitting reaction. The anodes with sufficient efficiency that are used today are made from precious and... 

    Design and Fabrication of Advanced Electrode Materials Based on Metal-organic Frameworks and Double Layered Hydroxides Using Hollow Copper Hydroxide Nanotubes Scaffold; Application to Nonenzymatic Glucose Sensor

    , M.Sc. Thesis Sharif University of Technology Khaki Sanati, Elnaz (Author) ; Shahrokhian, Saeed (Supervisor)
    Abstract
    One of the remarkable subject in advanced electrochemistry is, design and architecting new advanced materials with new electrochemical capabilities. One of the notable capabilities is electrocatalysis. Extensive researches are carrying out into the design and preparation of electrocatalyst materials to take advantage of these materials in fabrication of electrochemical sensors and storage/conversion devices. In this field nonoporous materials attracted a lot of attentions due to their unique features. In order to make use of the nanoporous materials as the electrocatalysts, these materials must be fabricated into continuous supported thin films on the electrode surface, which is the... 

    Manipulation of Electronic Structure in Boron Nitride Nanosheets to Improve Catalytic and Photocatalytic Properties

    , M.Sc. Thesis Sharif University of Technology Hemmati, Amir (Author) ; Simchi, Abdolreza (Supervisor)
    Abstract
    The variety of 2D materials and their wide range of properties, as well as numerous methods to manipulate them, have made this class of materials among prominent candidates for the future of the energy industry. Among the means available to tailor nanomaterials performance for such applications, introducing dopants and the creation of heteroatom-doped structures are of great interest. In this study, mixtures of urea, boric acid, and graphene oxide, as cheap and available precursors, were used to synthesize C-doped h-BN nanosheets. After the implementation of TGA/DSC to select a suitable calcination temperature of 950 C°, the samples were successfully synthesized with relatively precise... 

    Fabrication and Characterization of Conifecu and Three Dimensional Graphene Electrocatalyst Toward Oxygen Evolution Reaction

    , M.Sc. Thesis Sharif University of Technology Nourmohammadi Khiarak, Behnam (Author) ; Simchi, Abdolreza (Supervisor)
    Abstract
    Development of active, durable, cost effective, and stable electrocatalysts are of urgent need for various industrial fields including renewable energy systems such as water splitting. State-of-the-art catalysts suffer from high cost, poor catalytic activity in alkaline medium due to sluggish kinetics. We used one-step electrochemical deposition technique to prepare NiFeCu layered double hydroxide and CoNiFeCu dendritic porous structure on Ni-foam and flexible three-dimensional graphene (3DG) networks, respectively. The fabricated 3D electrodes have a high surface area, high electrical conductivity, and multiple interfaces which along with the synergetic effect of transition metals provided... 

    Synthesis, Characterization and Investigation of Electrocatalytic Activity of Nanoparticle/Cerium Oxide Composites in Oxygen Evolution and Reduction Reactions

    , M.Sc. Thesis Sharif University of Technology Moravvej, Heydar (Author) ; Taherinia, Davood (Supervisor)
    Abstract
    The sluggish kinetics of oxygen evolution and reduction on the surface of electrodes is a major problem for the widespread use of devices that are based on sustainable, renewable and clean technologies, such as fuel cells and metal–air batteries. Therefore, the development of efficient and cost–effective materials for the oxygen evolution (OER: Oxygen Evolution Reaction) and reduction reactions (ORR: Oxygen Reduction Reaction) is highly desirable. In recent years, Metal–organic frameworks (MOFs) and their derivatives, have drawn considerable attention as potential catalysts and electrocatalyst due to their high surface area and porous structure. In this study, cerium (IV) oxide was... 

    Modifying TiO2 Photoanodes by Co-Pi Electrocatalyst for Solar H2 Production

    , M.Sc. Thesis Sharif University of Technology Forouzandeh, Mojtaba (Author) ; Naseri, Naimeh (Supervisor)
    Abstract
    Currently, fossil fuels are the primary source of energy in the world. The increasing human need for energy and the limited resources of fossil fuels and their environmental side effects necessitate the search for other sources of energy. Considering its abundance and eco-compatibility, using solar energy is one of the best candidates for future. One of the methods to use solar energy is to convert and store it as hydrogen fuel by photoelectrochemical cells. In recent years, the main challenge with the production of hydrogen fuel in photoelectrochemical is optimizing them to increase efficiency. For this purpose, various approaches have been proposed such as the fabrication and use of... 

    Synthesis, Characterization and Investigation of Electrocatalytic Activity of Nanoparticle/Cerium Oxide Composites in Oxygen Evolution and Reduction Reactions

    , M.Sc. Thesis Sharif University of Technology Moravvej, Heydar (Author) ; Taherinia, Davood (Supervisor)
    Abstract
    The sluggish kinetics of oxygen evolution and reduction on the surface of electrodes is a major problem for the widespread use of devices that are based on sustainable, renewable and clean technologies, such as fuel cells and metal–air batteries. Therefore, the development of efficient and cost–effective materials for the oxygen evolution (OER: Oxygen Evolution Reaction) and reduction reactions (ORR: Oxygen Reduction Reaction) is highly desirable. In recent years, Metal–organic frameworks (MOFs) and their derivatives, have drawn considerable attention as potential catalysts and electrocatalyst due to their high surface area and porous structure. In this study, cerium (IV) oxide was... 

    Electrochemical Hydrogen Generation Using Metal Organic Frameworks Derived Catalysts

    , M.Sc. Thesis Sharif University of Technology Koohdareh, Amir Reza (Author) ; Gholami, Mohamad Reza (Supervisor)
    Abstract
    In recent years, the widespread investigation on multi-transition metal oxides that with two or more transition metal oxides, have been increased rapidly for electrochemical application due to low cost, high conductivity and good electrochemical performance other than single metal oxides. In this project, CuCo2O4 nanoparticles were firstly fabricated by decomposing of CuCo-MOF as the template. The as prepared samples were used to synthesis a new nanocomposite of MoS2 and CuCo2O4. The best ratio of the two component were optimized to prepare the best electrocatalyst for Hydrogen evolution reaction (HER). The structure of prepared nanocomposite were investigated by various techniques such as... 

    Investigation of Water Splitting Performance of Zeolitic Imidazolate Framework-67 and Graphene Quantum Dots Composite

    , M.Sc. Thesis Sharif University of Technology Kabirian Moghaddam, Mohammad Reza (Author) ; Simchi, Abdolreza (Supervisor)
    Abstract
    Depleting resources and heavy pollution of fossil fuels have drawn the world's attention to clean energy and the most ideal one is hydrogen. Water splitting is one of the most effective ways to produce hydrogen and due to slow kinetic rate different kind of catalysts (optical, electrochemical, etc.) are developed for this reaction. In this work a ZIF-67 and N-doped graphene quantum dots composite is developed and its electrocatalytic performance in oxygen evolution reaction is evaluated. The synthesized graphene quantum dots are between 2-4 nm and the incorporation of nitrogen atom in their structure was verified by FTIR analysis. The metal-organic framework which is produced in this work... 

    Investigaion Properties of Electrocatalytic Transition Metal Chalcogenids Nanocomposite in Hydrogen and Oxygen Evolution Reactions

    , M.Sc. Thesis Sharif University of Technology Moazzeni, Mohammad (Author) ; Taherinia, Davood (Supervisor)
    Abstract
    Electrochemical water splitting which consists of two half-reactions, namely; the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), is an important process in electrochemical energy storage and sustainable production of energy. Therefore, the development of cost-effective and efficient electrocatalysts for water splitting has attracted a lot of interest. In this work, a new nanocomposite was prepared from cobalt diselenide and cerium (IV) oxide derived from calcination of a cerium-based metal-organic framework (Ce-MOF), via hydrothermal and electrodeposition methods. The structure and morphology of synthesized materials were investigated by XRD, FE-SEM, EDX, and BET... 

    Investigation of Electrocatalytic Behavior of Some Transition Metal Oxides, Sulfides and Phosphides Nanostructures Toward Electrochemical Water Splitting

    , M.Sc. Thesis Sharif University of Technology Shamloofard, Maryam (Author) ; Shahrokhian, Saeed (Supervisor)
    Abstract
    Energy and the environment issues are among the most important concerns of the present age. Global demand for energy is growing rapidly and energy demand is projected to double in the coming years. However, today most of the energy consumption comes from fossil fuels, which have limited and unstable reserves and are among the sources of environmental pollution. Hence, the production and conversion of clean energy from renewable sources is considered as an intelligent solution to significantly reduce dependence on fossil fuels and protect the environment. Fuel cells, metal-air batteries, and water electrolysis are among the simplest, most efficient, and most reliable technologies among... 

    Design, Construction and Investigation of the Behavior of Electrocatalysts Based on Some Transition Multi Metals Nanostructures toward Electrochemical Water Splitting

    , Ph.D. Dissertation Sharif University of Technology Hafezi Kahnamouei, Mohammad (Author) ; Shahrokhian, Saeed (Supervisor)
    Abstract
    Energy and the environment issues are among the most important concerns of the present age. Global demand for energy is growing rapidly and energy demand is projected to double within the next 15 years. However, today most of the energy consumption comes from fossil fuels, which have limited and unstable reserves and are among the sources of environmental pollution. Hence, the production and conversion of clean energy from renewable sources is considered as an intelligent solution to significantly reduce dependence on fossil fuels and protect the environment. Fuel cells, metal-air batteries, and water electrolysis are among the simplest, most efficient, and most reliable technologies among... 

    Investigation of Electrocatalytic Activity of Metal-based Nanocomposites in the Reaction of Carbon Dioxide Reduction

    , M.Sc. Thesis Sharif University of Technology Hatami, Homayoun (Author) ; Bastani, Darioush (Supervisor) ; Taherinia, Davood (Supervisor)
    Abstract
    Emissions of carbon dioxide (CO2) from fossil fuels are a potential issue for the global climate. One way to meet this challenge is to electrochemically convert CO2 molecules to reduced carbon species such as formates, alcohols, hydrocarbons, etc., which is a difficult process due to the poor kinetics of CO2 reduction. Therefore, the use of catalysts, while preventing undesirable side reactions, can also play an important role in reducing CO2. In this study, a two-step synthesis of CuS (1, 5, 12, 24 hr) @ Cu-MOF has been reported as an advanced electrocatalyst for CO2 reduction in neutral pH environments. Bismuth has been used to improve the electrocatalytic properties of the samples. Bi-CuS... 

    Synthesis of Earth-Abundant Transition-Metal Based Nanocomposites as Bifunctional Electrocatalysts for the Overall Water Splitting

    , M.Sc. Thesis Sharif University of Technology Hajiloeyan Morafeh, Mojtaba (Author) ; Taherinia, Davoud (Supervisor)
    Abstract
    Sustainable and renewable energy sources are of fundamental importance in the development of strategic and sustainable economies. Therefore, in recent decades, water electrolysis has been widely used to produce pure hydrogen and oxygen without emitting carbon materials and is considered as a method for producing electrical energy alongside other renewable sources (such as wind and solar energy). Here, we report the synthesis of CoFe double-layered hydroxides (CoFe-LDHs) and their application as electrocatalysts for water splitting in alkaline environments. CoFe-LDHs were prepared via a new hydrothermal route from the metal-organic framework MIL-88A (MOF). The Co to Fe ratio in LDHs was... 

    Design and Fabrication Nanocomposite Modified Electrode Materials Based on Transition Metal Phosphide Using Copper Hydroxide Nanotubes as a Catalytic Substrate for Glucose Sensing in Non-Enzymatic Sensors

    , M.Sc. Thesis Sharif University of Technology Kazemi Abatari, Zeynab (Author) ; Shahrokhian, Saeed (Supervisor)
    Abstract
    In this study, transition metal phosphide, with a high accessible surface and abundant electroactive centers, was used as an electrocatalyst to fabrication an electrochemical sensor of Gloucose. The direct growth of thin film of nanocomposite can be considered as an efficient method to modify the electrode surface, and the application of these modified electrodes as electrochemical sensors. nanocomposite of transition metal phosphide (CuCoP) were directly grown on Cu(OH)2 nanotubes (as-prepared on GCE) in order to design hierarchical core-shell nanostructure with using efficient, inexpensive and fast method. Here, Cu(OH)2 nanotubes not only served as substrate, but also steer the CuCoP to... 

    Electrochemical Deposition of Co-Mn LDH/Ni-Co-S as an Electrocatalyst for Electrochemical Water Splitting Reactions

    , M.Sc. Thesis Sharif University of Technology Askarzadeh Torghabeh, Mostafa (Author) ; Ghorbani, Mohammad (Supervisor) ; Barati Darband, Ghasem (Co-Supervisor)
    Abstract
    The development of alternative energy sources is a prominent area of scientific research. Hydrogen, with its exceptional energy density, has emerged as a particularly promising candidate among these new energy sources. An effective technique for generating hydrogen is through the electrochemical process of water splitting. To enhance this process, it is crucial to investigate the development of electrocatalysts with high electrocatalytic activity. Among the potential options, sulfides of transition metals show promise. An essential difficulty in electrochemical water splitting is the development of a bifunctional catalyst that is both active and stable for both the hydrogen evolution...