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cerium-oxide
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Comparison of the Performance of Nanostructured Metal Oxides and Metal Sulfides as Electrode Active Materials in the Construction of Supercapacitors
, M.Sc. Thesis Sharif University of Technology ; Ghotbi, Cyrus (Supervisor) ; Khorasheh, Farhad (Supervisor) ; Asgharinezhad, Ali Akbar (Supervisor) ; larimi, Afsaneh Sadat (Supervisor)
Abstract
High-capacity electrode materials are crucial for enhancing the performance of supercapacitors. Transition metal sulfides are considered promising materials for supercapacitor applications due to their high theoretical capacity and good electrical conductivity. Additionally, cerium oxide improves the performance of supercapacitors due to stable reversible oxidation states and greatly supported the faradaic redox reaction. In this study, ceria nanosheets incorporated with MCoS (M=Mn, Zn, Cu) were synthesized successfully through a facile hydrothermal method by sulfidation of MCo LDH/CeO2. The structural and morphological characteristics were analyzed using X-ray diffraction, scanning electron...
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 ; 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...
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 ; 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...
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...
An investigation on the influence of milling time and calcination temperature on the characterization of nano cerium oxide powder synthesized by mechanochemical route
, Article Materials Research Bulletin ; Volume 47, Issue 11 , 2012 , Pages 3586-3591 ; 00255408 (ISSN) ; Amoozegar, Z ; Sadrnezhaad, S. K ; Sharif University of Technology
2012
Abstract
The synthesis of nano-sized CeO 2 powder was investigated via mechanochemical reactions between hydrate cerium chloride and sodium hydroxide as the starting materials. The process was followed by a subsequent calcination procedure. Characterization of as-synthesized powder was performed using X-ray diffraction, FTIR spectroscopy, Brunner-Emmett-Teller (BET) nitrogen gas absorption, scanning electron microscopy (SEM) and particle size analyzer (PSA). The precursors were milled for different milling times and then were subjected to different heat treatment procedure at variable temperatures from 100 to 700 °C. According to the results, milling time and calcination temperatures induce...
MOD growth of epitaxial cerium oxide buffer layer on LAO substrates for fabrication of c-axis oriented YBCO
, Article Micro and Nano Letters ; Volume 7, Issue 10 , 2012 , Pages 1008-1010 ; 17500443 (ISSN) ; Foroughi Abari, F ; Vesaghi, M. A ; Fardmanesh, M ; Sharif University of Technology
2012
Abstract
Epitaxial cerium oxide (CeO2) buffer layer has been grown on lanthanum aluminate (LAO) single crystal substrates for fabrication of c-axis oriented YBa2Cu3O7-x (YBCO). Precursor solution of cerium acetylacetonates with viscosity of 0.6 centipoises was spin coated on the 1×1 cm area LAO substrates. The calcination was carried out by very slow ramp (1°C per minute) until the final temperature of 500°C in oxygen flow to remove most of the organic compounds. The final heat treatment has been done at 780°C by a ramp of 20° per minute in gas flow of mixed argon-oxygen with 5 Pa partial pressure of oxygen. The thickness of the deposited CeO2 buffer layer was 20 nm. Then, 100 nm thick YBCO film was...
Assembly of CeO 2-TiO 2 nanoparticles prepared in room temperature ionic liquid on graphene nanosheets for photocatalytic degradation of pollutants
, Article Journal of Hazardous Materials ; Volume 199-200 , 2012 , Pages 170-178 ; 03043894 (ISSN) ; Setayesh, S. R ; Habibi Yangjeh, A ; Hormozi Nezhad, M. R ; Gholami, M. R ; Sharif University of Technology
2012
Abstract
CeO 2-TiO 2 nanoparticles were prepared by the sol-gel process using 2-hydroxylethylammonium formate as room-temperature ionic liquid and calcined at different temperatures (500-700°C). CeO 2-TiO 2-graphene nanocomposites were prepared by hydrothermal reaction of graphene oxide with CeO 2-TiO 2 nanoparticles in aqueous solution of ethanol. The photocatalysts were characterized by X-ray diffraction, BET surface area, diffuse reflectance spectroscopy, scanning electron microscopy, and Fourier transformed infrared techniques. The results demonstrate that the room-temperature ionic liquid inhibits the anatase-rutile phase transformation. This effect was promoted by addition of CeO 2 to TiO 2....
Electrophoretic deposition of ZnO–CeO2 mixed oxide nanoparticles
, Article Journal of the American Ceramic Society ; Volume 100, Issue 3 , 2017 , Pages 901-910 ; 00027820 (ISSN) ; Aliofkhazraei, M ; Hosseinali, M ; Sharif University of Technology
Blackwell Publishing Inc
2017
Abstract
ZnO–CeO2 nanoparticles were synthesized by microwave combustion and deposited by electrophoretic deposition (EPD). The effect of using two different alcohols, ethanol and methanol, was investigated on EPD behavior and morphology of deposited film. Moreover, the effect of concentration of nanoparticles and applied voltage on the mass of deposit and the variation in the current density were investigated. With a change in the alcohol type, the surface morphology of deposition changed and some voids were observed on the deposition surface in ethanol. In all cases, with increasing concentration of nanoparticles in suspension, the number of developed cracks increased. Besides, a rise in voltage...
Improved H2 production from the APR of polyols in a microreactor utilizing Pt supported on a CeO2–Al2O3 structured catalyst
, Article International Journal of Hydrogen Energy ; Volume 43, Issue 48 , 2018 , Pages 21777-21790 ; 03603199 (ISSN) ; Kazemeini, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this research, the activity and selectivity of a platinum-based catalyst for H2 production through aqueous phase reforming (APR) in a fixed-bed reactor (FBR) as well as, a structured catalyst microreactor (MR) were investigated. In this venue, first, an in-house designed MR was fabricated and the catalytic material was deposited on the channel walls of this steel made reactor. After verification of the stability of the coated layer, the prepared reactor was employed to investigate the APR reaction. In this regard, APR of the ethylene glycol and glycerol over Pt/Al2O3 and Pt/CeO2–Al2O3 catalyst were conducted in an MR and FBR. Obtained results demonstrated that employing Pt/CeO2–Al2O3 as a...
Fabrication of novel ternary Au/CeO2@g-C3N4 nanocomposite: kinetics and mechanism investigation of 4-nitrophenol reduction, and benzyl alcohol oxidation
, Article Applied Physics A: Materials Science and Processing ; Volume 124, Issue 6 , 2018 ; 09478396 (ISSN) ; Gholami, M. R ; Sharif University of Technology
Springer Verlag
2018
Abstract
Abstract: Au nanoparticles supported on cerium oxide/graphitic carbon nitride (CeO2@g-C3N4) was synthesized and used as heterogeneous catalyst in redox reaction. The catalyst was characterized by different techniques such as FT-IR, XRD, FE-SEM, EDS, TEM, BET, TGA, and ICP. The as-prepared ternary nanocomposite was used as an effective catalyst for the reduction of toxic 4-nitrophenol to useful 4-aminophenol by NaBH4. The rate constant value of reduction reaction reached up to 0.106 s−1 by Au/CeO2@g-C3N4, which was 3.8, and 8.8 times higher than that of Au@CeO2 (0.028 s−1), and Au@g-C3N4 (0.012 s−1) nanocomposites, respectively. The superior catalytic performance of as-prepared catalyst in...
Synthesis and characterization of photocatalytically active crumpled-shape nanocomposites of nitrogen and sulfur co-doped ZnO–CeO2
, Article Solar Energy Materials and Solar Cells ; Volume 203 , 2019 ; 09270248 (ISSN) ; Sabour Rouh Aghdam, A ; Nazari, M ; Bayat, A ; Saievar Iranizad, E ; Najafi Liavali, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
In this study, crumpled-shape nanocomposite of nitrogen and sulfur co-doped ZnO–CeO2 (NSZC) was deposited on FTO substrate using one-step ultrasonic spray pyrolysis. Zinc acetate, cerium nitrate, and thiourea were dissolved in deionized water and used as starting solution. The samples were characterized using FESEM, XRD, UV–vis spectroscopy, EIS, and PL. The as-prepared nitrogen and sulfur co-doped ZnO–CeO2 nanocomposites were evaluated as high photocatalysts for degradation of methyl orange. Nearly 100% photocatalytic degradation of methyl orange was achieved for 180 min. The photoluminescence and electrochemical impedance spectroscopy revealed that co-doping of nitrogen and sulfur could...
Efficient degradation of AO7 by ceria-delafossite nanocomposite with non-inert support as a synergistic catalyst in electro-fenton process
, Article Environmental Pollution ; Volume 252 , 2019 , Pages 749-757 ; 02697491 (ISSN) ; Tootoonchian, P ; Setayesh, S. R ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
CuFeO2/CeO2 as a novel synergistic catalyst for EF removal of organic pollutants was synthesized. © 2019 Elsevier Ltd
Synthesis, first-principle simulation, and application of three-dimensional ceria nanoparticles/graphene nanocomposite for non-enzymatic hydrogen peroxide detection
, Article Journal of the Electrochemical Society ; Volume 166, Issue 5 , 2019 , Pages H3167-H3174 ; 00134651 (ISSN) ; Hatamie, A ; Berahman, M ; Simchi, M ; Angizi, S ; Rahmati, R ; Kennedy, J ; Simchi, A ; Sharif University of Technology
Electrochemical Society Inc
2019
Abstract
Owing to the exceptional properties of graphene and the crucial role of substrate on the performance of electrochemical biosensors, several graphene-based hybrid structures have recently emerged, yielding improved selectivity and sensitivity. To date, most of the reported biosensors utilize solution-driven graphene flakes with drawbacks of low conductivity (due to high inter-junction contact resistant) and structural fragility. Herein, we present a conductive three-dimensional CeO2 semiconductor nanoparticles/graphene nanocomposite, as a platform for sensitive detection of hydrogen peroxide, an important molecule in fundamental biological processes. The 3D conductive graphene architecture is...
Synthesis, first-principle simulation, and application of three-dimensional ceria nanoparticles/graphene nanocomposite for non-enzymatic hydrogen peroxide detection
, Article Journal of the Electrochemical Society ; Volume 166, Issue 5 , 2019 , Pages H3167-H3174 ; 00134651 (ISSN) ; Hatamie, A ; Berahman, M ; Simchi, M ; Angizi, S ; Rahmati, R ; Kennedy, J ; Simchi, A ; Sharif University of Technology
Electrochemical Society Inc
2019
Abstract
Owing to the exceptional properties of graphene and the crucial role of substrate on the performance of electrochemical biosensors, several graphene-based hybrid structures have recently emerged, yielding improved selectivity and sensitivity. To date, most of the reported biosensors utilize solution-driven graphene flakes with drawbacks of low conductivity (due to high inter-junction contact resistant) and structural fragility. Herein, we present a conductive three-dimensional CeO2 semiconductor nanoparticles/graphene nanocomposite, as a platform for sensitive detection of hydrogen peroxide, an important molecule in fundamental biological processes. The 3D conductive graphene architecture is...
Comparison between electrochemical and photoelectrochemical detection of dopamine based on titania-ceria-graphene quantum dots nanocomposite
, Article Biosensors and Bioelectronics ; Volume 151 , 2020 ; Bagherzadeh, M ; Nemati, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this study, titania-ceria-graphene quantum dot (TC-GQD) nanocomposite was synthesized by hydrothermal method for the first time. The prepared nanomaterials were characterized by XRD, FTIR dynamic light scattering (DLS), FESEM, HRTEM, and EDX spectroscopy along with elemental mapping. The synergistic effect of the nanocomposite components was studied by diffuse reflectance spectroscopy (DRS) and electrical conductivity meter. The results showed that band gap of TC-GQD nanocomposite was shifted to visible lights relative to its components (1.3 eV), and electrical conductivity of the sample was significant increased to 89.5 μS cm−1. After chemical and physical characterization, prepared new...
Engineered FeVO4/CeO2 nanocomposite as a two-way superior electro-Fenton catalyst for model and real wastewater treatment
, Article Journal of Environmental Sciences (China) ; Volume 97 , 2020 , Pages 110-119 ; Nazari, P ; Maghbool, R ; Sharif University of Technology
Chinese Academy of Sciences
2020
Abstract
FeVO4/CeO2 was applied in the electro-Fenton (EF) degradation of Methyl Orange (MO) as a model of wastewater pollution. The results of the characterization techniques indicate that FeVO4 with triclinic structure and face-centered cubic fluorite CeO2 maintained their structures during the nanocomposite synthesis. The effect of applied current intensity, initial pollutant concentration, initial pH, and catalyst weight was investigated. The MO removal reached 96.31% and chemical oxygen demand (COD) removal 70% for 60 min of the reaction. The presence of CeO2 in the nanocomposite plays a key role in H2O2 electro-generation as a significant factor in the electro-Fenton (EF) system. The metal...
Processing study of gel-cast tubular porous NiO/SDC composite materials from gel-combustion synthesized nanopowder
, Article Journal of Sol-Gel Science and Technology ; Volume 97, Issue 3 , 2021 , Pages 581-592 ; 09280707 (ISSN) ; khakpour, Z ; Faghihi sani, M. A ; Kazemzad, M ; Sharif University of Technology
Springer
2021
Abstract
In the present research, NiO–SDC (Samarium doped Ceria) nanopowder was synthesized through sol–gel combustion method using citric acid as a reducing agent (fuel) and metal nitrates as an oxidant. The characteristics of the synthesized powder were thoroughly analyzed by DTA/TG, XRD, BET and FESEM/EDX. Tubular gel-casted porous specimens of NiO–SDC (50:50 wt%) composite materials were produced after stabilizing suspensions of composite powder in an aqueous environment by addition of 3 wt% dispersant and 2.5 wt% agar as the gel builder. The effect of Dolapix CE64 as a dispersant, agar as a gel-builder and the amount of solid loadings on the processing and properties of porous ceramics was...
Hybrid of cerium dioxide nanoparticles/reduced graphene oxide as an electrode material for supercapacitor applications
, Article Journal of Physics and Chemistry of Solids ; Volume 159 , 2021 ; 00223697 (ISSN) ; Askari, M. B ; Beydaghi, H ; Rastgoo Deylami, M ; Rozati, S. M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
In this study, we prepared cerium oxide (CeO2) hybridized with reduced graphene oxide (rGO) nanosheets using the hydrothermal method. CeO2 and CeO2/rGO were evaluated as electrode materials for use in supercapacitor applications. The structure and morphology of the synthesized materials were investigated. Cyclic voltammetry tests determined a high specific capacitance of 581 F g−1 for CeO2/rGO at a scan rate of 10 mV s−1 in 2 M KOH. In addition, the CeO2/rGO electrode retained 91 % of its initial capacitance after 5000 consecutive cycles, thereby indicating its excellent electrochemical stability. The excellent stability of CeO2/rGO was due to a synergistic effect between CeO2 and rGO. CeO2...
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...
Selective fabrication of robust and multifunctional super nonwetting surfaces by diverse modifications of zirconia-ceria nanocomposites
, Article Langmuir ; Volume 38, Issue 30 , 2022 , Pages 9195-9209 ; 07437463 (ISSN) ; Zandi, A ; Ghazanfari, M. H ; Khezrnejad, A ; Fatemi, M ; Molaei Dehkordi, A ; Sharif University of Technology
American Chemical Society
2022
Abstract
The creation of surfaces with various super nonwetting properties is an ongoing challenge. We report diverse modifications of novel synthesized zirconia-ceria nanocomposites by different low surface energy agents to fabricate nanofluids capable of regulating surface wettability of mineral substrates to achieve selective superhydrophobic, superoleophobic-superhydrophilic, and superamphiphobic conditions. Surfaces treated with these nanofluids offer self-cleaning properties and effortless rolling-off behavior with sliding angles ≤7° for several liquids with surface tensions between 26 and 72.1 mN/m. The superamphiphobic nanofluid coating imparts nonstick properties to a solid surface whereby...