Search for: hydroxides
Total 129 records
Electrocatalytic oxidation of methane at nickel hydroxide modified nickel electrode in alkaline solution, Article Electrochemistry Communications ; Volume 5, Issue 2 , 2003 , Pages 184-188 ; 13882481 (ISSN) ; Mahjani, M. G ; Heli, H ; Gobal, F ; Heydarpoor, M ; Sharif University of Technology
Elsevier Inc 2003
Nickel hydroxide modified nickel electrodes prepared by cycling the potential of a nickel electrode in alkaline solution exhibited electrocatalytic activity for the oxidation of methane in alkaline media. In the presence of methane the oxidation peak current of nickel hydroxide increases while that of the reverse process decreases. This is attributed to the mediation of nickel species, probably β-NiOOH phase, in the process of electrocatalysis. The mechanism of methane oxidation has also been discussed in terms of the formations of intermediates normally encountered in small organics electro-oxidation. It has also been suggested that in the further oxidation of the intermediates, ions in the...
Article Scientia Iranica ; Volume 14, Issue 2 , 2007 , Pages 169-173 ; 10263098 (ISSN) ; Alamolhoda, A. A ; Hashemian, S. J ; Sharif University of Technology
Sharif University of Technology 2007
The compound, lead hydroxide Pb6O4(OH)4, was prepared by a method used for the first time in the authors laboratory. The compound was identified by XRD and it's purity was determined by analytical methods (100%). The thermal characteristics of this compound were investigated by using a thermogravimetry (TGA). This compound was found to be stable at room temperature and at 160°C will decompose completely to produce lead (II) oxide. © Sharif University of Technology, April 2007
Article Egyptian Journal of Petroleum ; Volume 28, Issue 2 , 2019 , Pages 225-231 ; 11100621 (ISSN) ; Khorasheh, F ; Soltanali, S ; Tayyebi, S ; Sharif University of Technology
Egyptian Petroleum Research Institute 2019
Desulfurization by molten caustic leaching (MCL) at 400–500 °C has been investigated in order to reduce the sulfur content of petroleum coke. Effective parameters on desulfurization of petroleum coke, other than temperature, include alkali to feed (petroleum coke) mass ratio, time and mesh size in the ranges of 0.5–1.5, 1–3 h and 200–600 µm, respectively. In this work, petroleum coke desulfurization conditions using solid KOH have been studied. Maximum petroleum coke desulfurization by MCL method has been obtained by Taguchi L9 design using alkali to feed mass ratio of 1, temperature of 600 °C, time of 2 h and mesh size of 200 µm. The changes in the main groups on the coke surface have been...
Facile preparation of a highly sensitive non-enzymatic glucose sensor based on the composite of Cu(OH)2 nanotubes arrays and conductive polypyrrole, Article Microchemical Journal ; Volume 169 , 2021 ; 0026265X (ISSN) ; Shahrokhian, S ; Hafezi Kahnamouei, M ; Sharif University of Technology
Elsevier Inc 2021
A novel amperometric non-enzymatic glucose sensor is designed by the facile preparation method. It is made by electrodeposition of Cu clusters and converting them to Cu(OH)2 nanotubes (Cu(OH)2NTs) arrays along with thin-film electro-polymerized of spindle-shaped polypyrrole (PPy@Cu(OH)2NTs), which have been doped by using sodium Benzene-1,3-disulfonate as an anion dopant. Various electrochemical methods investigate the electrochemical performance of the modified electrode toward glucose detection. Under the optimized conditions, a significant electrochemical response improvement is observed toward the electro-oxidation of glucose on the PPy@Cu(OH)2NTs electrode's surface relative to the...
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 ; Shahrokhian, Saeed ; IrajiZad, Azam
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...
Investigating the Electrochemical Behavior of Co-Zn Sulfides and Hydroxides on Copper Oxide Nano-structures Grown on Copper Foam for Application in Electrochemical Supercapacitors, M.Sc. Thesis Sharif University of Technology ; Shahrokhian, Saeed
In the first part, Co-Zn hydroxides were deposited onto CuO nanorods, and their electrochemical behavior and capacitive performance were investigated. To this end, Cu(OH)2 nanorods were grown on copper foam through a chemical process. Then, Cu(OH)2 were converted to CuO nanorods via a calcination process. In the next step, Co-Zn-OH sheets were electrodeposited on CuO nanorods. FE-SEM images of the prepared electrodes demonstrate the formation of Co-Zn-OH nanosheets onto CuO nanorods. Crucial electrochemical evaluations such as cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), rate capability, and electrochemical impedance spectroscopy (EIS) were carried out. According to the...
Investigating and modeling the cleaning-in-place process for retrieving the membrane permeate flux: Case study of hydrophilic polyethersulfone (PES), Article Journal of the Taiwan Institute of Chemical Engineers ; Volume 62 , May , 2016 , Pages 150–157 ; 18761070 (ISSN) ; Shayegan, J ; Sargolzaei, J ; Sharif University of Technology
Taiwan Institute of Chemical Engineers 2016
In this work the effects of backwash pressure, duration of acid and sodium hydroxide backwashing, sodium hydroxide concentration, and the duration of forward washing on performance of permeate flux recovery (PFR) were investigated. A two-level fractional factorial design (FFD) was used to design the experiments. The ability of back propagation neural network (BPNN) and radial basis function neural network (RBFNN) in predicting the performance of cleaning-in-place (CIP) of hydrophilic polyethersulfone (PES) membrane were investigated. It is found that BPNN has better ability in predicting the PFR performance than RBFNN. The best architecture of BPNN was a network consisting of 1 hidden layer...
In-situ electrochemical exfoliation of Highly Oriented Pyrolytic Graphite as a new substrate for electrodeposition of flower like nickel hydroxide: Application as a new high-performance supercapacitor, Article Electrochimica Acta ; Volume 206 , 2016 , Pages 317-327 ; 00134686 (ISSN) ; Mohammadi, R ; Amini, M. K ; Sharif University of Technology
Elsevier Ltd 2016
Demand for more efficient energy storage devices stimulates efforts to search and develop new materials and composites with promising properties. In this regard, composite materials, including carbonaceous materials and metal oxides have attracted a great attention due to better electrochemical performance as compared to their single material analogues. For the first time, herein, we report a new and simple procedure for preparing porous highly oriented pyrolytic graphite/nickel hydroxide composite (P-HOPG/Ni(OH)2) via a fast and simple two-step electrochemical method including potentiostatic routes. In the first step, a low anodic potential (2 V) was applied to pristine HOPG in 0.5 M H2SO4...
Pt–NiO–Al2O3/G derived from graphene-supported layered double hydroxide as efficient catalyst for p-nitrophenol reduction, Article Research on Chemical Intermediates ; Volume 43, Issue 10 , 2017 , Pages 5829-5839 ; 09226168 (ISSN) ; Gholami, M. R ; Sharif University of Technology
The present work reports the synthesis of a Pt-modified NiO–Al2O3 nanocomposite derived from graphene-supported layered double hydroxide (Pt–NiO/G) and demonstrates its catalytic activity. The resulting Pt–NiO/G nanocomposite was characterized by FT-IR, XRD, FE-SEM, TEM and XPS techniques and used for catalytic reduction of p-nitrophenol (P-NP) to p-aminophenol (P-AP). The influence of graphene on catalytic activity was comparatively considered by preparation of Pt–NiO nanoparticles derived from layered double hydroxide. The superior catalytic performance of Pt–NiO/G was ascribed to the synergistic effect between Pt and NiO. Furthermore, reduction of P-NP was considered to follow a...
M.Sc. Thesis Sharif University of Technology ; Musavi, Abbas ; Bastani, Dariush
Sodium Hydroxide production industry is among the largest chemical industries that annually produces 66 million tons worldwide. NaOH which is produced through electrochemical cells needs to be further enriched. The use of membrane technology as a substitute for conventional processes has been a point of interest. Thin film composite membrane is among favorable membrane because of its ability to be customized layer by layer individually. In this thesis, for the purpose of making an optimized membrane for NaOH enrichment, we studied the preparation conditions and witnessed that by increasing MPD from 1.5 %wt. to 4.5%wt. The flux experiences a minimum at 3.5%wt, which is the maximum for...
Article Carbohydrate Polymers ; Volume 92, Issue 2 , 2013 , Pages 2252-2256 ; 01448617 (ISSN) ; Hosseini, S. H ; Fakoorpoor, S. M ; Sharif University of Technology
In this work, a novel heterogeneous organocatalyst was synthesized by immobilization of hydroxide ions on the modified salep as a natural polymer. Because of the grafting of ionic polymer chains onto the salep backbone, catalyst has high loading level of hydroxide ions (3.01 mmol/g). The resulting catalyst shows excellent activity in the synthesis of 4H-benzo[b]pyrans in water at room temperature in short reaction times. The present catalyst and protocol represent a simple, ecologically safe and cost-effective route to synthesize 4H-benzo[b]pyrans with high product yield, as well as easy catalyst recycling
Oxidation of Sulfides and Olefins in the Presence of Nanocluster Polyoxotungstate–intercalated Layered Double Hydroxide Nanoparticles as a Catalyst, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba
In this study, polyoxometalate (POM) intercalated in the layered double hydroxide (LDH) was synthesized by a selective ion-exchange method. For this purpose, the nanocluster [VW12O40]3- was immobilized on the Mg2+/A13+/Cl–LDH support. The heterogeneous catalyst was characterized by FT-IR, XRD, SEM and analysis of ICP. The LDH-POM was applied as a catalyst in efficient oxidation of sulfides to sulfoxides using UHP as oxidant and CH3OH/ CH¬2¬Cl¬2 ¬as a solvent at room temperature, as well as epoxidation of olefins using TBHP as an oxidants and C¬2H4Cl2 as a solvent in 84°C. This catalyst showed excellent catalytic activities for a substrate/catalyst ratio (200:1). For example, this catalytic...
M.Sc. Thesis Sharif University of Technology ; Borghei, Mehdi
Activated Carbon as a highly efficient and low price absorbent has manifold functions in separation and absorption processes in liquid or gas phases. These applications in liquid phase include bleaching in sugar syrup, water and wastewater treatment and in gas phase utilizing them in gas masks and solvent recycling process. Wide variety of base materials could be used to produce activated carbon. For instance rare cellulose materials -wood, coconut shell, Pyrenees and agricultural wastes-, carbon materials-coal, petroleum coke, tar- and polymer materials- tires and plastics wastes- could be mentioned. In this thesis, feasibility of producing activated carbon based on using walnut, almond...
M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad ; Soltanali, Saeed ; Baghalha, Morteza ; Tayebi, Shokufeh
In this study, desulfurization of petroleum coke has been investigated for use in aluminum industry. To reduce sulfur content in petroleum coke, desulfurization has been investigated by two methods of solvent extraction and molten caustic leaching. The method of molten caustic leaching at temperatures of 400-600 °C has been investigated. Other effective parameters on the desulfurization of petroleum coke are the mass ratio of alkali to feed (petroleum coke) in the range of 0.5-1.5 and the time of 1-3 hour and the mesh size of 200-600 micron. In this study, the conditions of desulfurization of petroleum coke using potassium hydroxide have been investigated. Results show that by using the...
Corrosion Protection of Aluminium by Smart Coatings Containing Layered Double Hydroxide (LDH) Nanocontainers, Ph.D. Dissertation Sharif University of Technology ; Afshar, Abdollah
Smart coatings which prevent corrosion by several mechanisms recently have been carefully planned. One of these mechanisms is the use of ion exchangers like Layered Double Hydroxide (LDH) in the coating network. In this study, the LDH containing a kind of green inhibitor (sodium molybdate) was synthesized and utilized in a Poly-Vinyl Alcohol (PVA) base coating applied on the aluminium (5054 series) surface. After evaluating the LDH performance, the inhibitor release from the LDH crystals was examined by changing significant parameters like MII/MIII (the molar ratio of divalent ions into trivalent ions), pH, aging time and temperature. Considering the LDH morphology or the thickness of the...
Design and Fabrication of Supercapacitors Based on Modified Carbon Nanospheres Using Transition Metal Oxide/Hydroxide, M.Sc. Thesis Sharif University of Technology ; Shahrokhian, Saeed
Herein a simple tow step method is developed to design hierarchical binder free structure of binary nickel cobalt carbonate hydroxide decorated hydrothermal carbon sphere. First carbon sphere were synthesized on nickel foam via hydrothermal process using glucose solution followed by carbonization process. Ni Co carbonate hydroxide core shell array were directly grown on binder free carbon spheres using hydrothermal method. The synthesized electrode afforded high specific capacitance (497/83 mAhg-1 at a current density of 1/4 A g-1) and good cyclic stability (85% after 1500 charge / discharge cycles). EIS measurement showed negligible internal resistance (0.638 Ω) which is attributed to the...
M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi
Nowadays, due to the increasing importance of environmental issues, cement replacement has been considered by many researchers .Determination of behavioral characteristics and fracture of materials such as fracture hardness and energy is used to describe the formation and progress of cracks in new building materials. On the other hand, one of the concrete that can be replaced ordinary concrete is slag concrete. Slag concrete is in the category of Geopolymer Concrete. This concrete is produced by activation of puzzulanic material by alkaline solution.There have not been many studies on the failure of slag concrete. Therefore, in this study, the mechanical properties of slag concrete were...
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
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....
Synthesis and Performance Evaluation of FeOOH Elechtrocatalyst Supported on Nickel Foam for Oxygen Evolution Reaction, M.Sc. Thesis Sharif University of Technology ; Moshfegh, Alireza ; Naseri, Naimeh
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...
M.Sc. Thesis Sharif University of Technology ; Naseri, Naimeh
One of the pillars of reaching a steady development is to utilize sustainable energies. In order to make use of these modern means of energy, appropriate energy storage devices are inevitable. One of the families of these devices is the supercapacitors. Moving toward the 4th industrial revolution, we are encountering modern technologies such as internet of things and wearable electronics. Therefore, designing and fabricating microsupercapacitors is of paramount importance in order to reduce the weight and size of these devices. Cobalt and nickel are considered as two important elements to be used in synthesizing supercapacitive materials and composites, because of their good electrochemical...