Effect of the ruthenium incorporation on iron oxide phases synthesis, Fe2O3 and Fe3O4, at low annealing temperature

2020 ◽  
Vol 242 ◽  
pp. 122272
Author(s):  
Beya Ouertani ◽  
Ghada Bidouk ◽  
Rachid Ouertani ◽  
Bertrand Theys ◽  
Hatem Ezzaouia
Keyword(s):  
Iron Oxide ◽  
Annealing Temperature ◽  
Oxide Phases

scholarly journals Influence of annealing temperature on the morphology and the supercapacitance behavior of iron oxide nanotube (Fe-NT)

2014 ◽  
Vol 272 ◽  
pp. 766-775 ◽  
Author(s):  
Biplab Sarma ◽  
Abraham L. Jurovitzki ◽  
York R. Smith ◽  
Rupashree S. Ray ◽  
Mano Misra
Keyword(s):  
Iron Oxide ◽  
Annealing Temperature

Nanoparticles generated by combining hot wall and microwave plasma chemical vapor synthesis

MRS Advances ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 213-218
Author(s):  
Alexander Levish ◽  
Markus Winterer
Keyword(s):  
Iron Oxide ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Chemical Vapor ◽  
Process Window ◽  
Chemical Vapor Synthesis ◽  
Second Stage ◽  
Structure Surface ◽  
Oxide Phases ◽  
Precursor Decomposition

ABSTRACTControlling the oxidation state of iron and the crystal structure of iron containing compounds is the key to improved materials such as iron oxide nanoparticles for cancer treatment or heterogeneous catalysis. Iron oxides contain iron in different oxidation states and form different phases for one valence state (α-Fe3+2O2-3, β- Fe3+2O-32, etc.). Chemical vapor synthesis (CVS) allows the reproducible production of pure nanocrystals with narrow size distribution where particle formation and growth take place in the gas phase. Through the controlled variation of synthesis parameters CVS enables the synthesis of diverse iron oxide phases. In this study the energy for the CVS process is supplied by a hot wall furnace and a microwave plasma. The advantage of an plasma reactor as the first CVS stage is the fast and complete precursor decomposition at low temperatures. This results in a larger process window for the hot wall reactor in the second stage. The nanoparticles are examined regarding their structure, surface and valence by XRD and TEM.

scholarly journals Characterization of the iron oxide phases formed during the synthesis of core–shell FexOy@C nanoparticles modified with Ag

2020 ◽  
Vol 31 (39) ◽  
pp. 395703
Author(s):  
D A Petrov ◽  
C -R Lin ◽  
R D Ivantsov ◽  
S G Ovchinnikov ◽  
S M Zharkov ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Core Shell ◽  
Oxide Phases

scholarly journals Impact of Gadolinium on the Structure and Magnetic Properties of Nanocrystalline Powders of Iron Oxides Produced by the Extraction-Pyrolytic Method

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4147
Author(s):  
Vera Serga ◽  
Regina Burve ◽  
Mikhail Maiorov ◽  
Aija Krumina ◽  
Ramūnas Skaudžius ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Thermal Treatment ◽  
Iron Oxides ◽  
Caproic Acid ◽  
Transformation Process ◽  
Nanocrystalline Powders ◽  
Preparation Conditions ◽  
Oxide Phases

Interest in magnetic nanoparticles is primarily due to their practical use. In this work, for the production of nanocrystalline powders of pure and gadolinium doped iron oxides, the extraction-pyrolytic method (EPM) was used. As a precursor, either iron-containing extract (iron (III) caproate in caproic acid) or its mixture with gadolinium-containing extract (gadolinium (III) valerate in valeric acid) was used. The mixed precursor contained 0.5 mol %, 2.5 mol %, 12.5 mol %, 50 mol %, and 75 mol % gadolinium in relation to the iron content. The formation of iron oxide phases, depending on the preparation conditions, was investigated. According to the results obtained, it was demonstrated that the presence of more than 2.5 mol % gadolinium additive in the mixed precursor inhibits the magnetite-to-hematite transformation process during thermal treatment. Produced samples were characterized by XRD and SEM methods, and the magnetic properties were studied.

Effect of variation of molar ratio (pH) on the crystallization of iron oxide phases in microwave hydrothermal synthesis

2002 ◽  
Vol 57 (2) ◽  
pp. 457-462 ◽  
Author(s):  
S.R Dhage ◽  
Y.B Khollam ◽  
H.S Potdar ◽  
S.B Deshpande ◽  
P.P Bakare ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Hydrothermal Synthesis ◽  
Molar Ratio ◽  
Microwave Hydrothermal ◽  
Oxide Phases

Synthesis of Metal Oxide Hollow Nanoparticles by Chemical Vapor Condensation Process

2006 ◽  
Vol 317-318 ◽  
pp. 219-222 ◽  
Author(s):  
C.W. Lee ◽  
S.G. Kim ◽  
Jai Sung Lee
Keyword(s):  
Iron Oxide ◽  
Reaction Temperature ◽  
Chemical Vapor ◽  
Phase Evolution ◽  
Vapor Condensation ◽  
Condensation Process ◽  
Iron Oxide Particles ◽  
Hollow Nanoparticles ◽  
Chemical Vapor Condensation ◽  
Oxide Phases

The influence of reaction temperature on phase evolution of iron oxide hollow nanoparticles during chemical vapor condensation (CVC) process using iron acetylacetonate was investigated. X-ray diffraction (XRD) analyses revealed that three iron oxide phases (α-Fe2O3, γ-Fe2O3, and Fe3O4) and a mixture of β-Fe2O3 and small amount of γ-Fe2O3 were synthesized at 700oC and 900oC, respectively. TEM observation disclosed that the iron oxide particles are almost composed of hollow structured nanoparticles of 10~20 nm in size and 3~5 nm in shell thickness. This result implies that reaction temperature determining various reaction parameters plays an important role for the phase- and structural evolutions of iron oxide hollow nanoparticles. Especially, the present investigation attempted to explain temperature dependence of the phase evolution of β-Fe2O3 hollow nanoparticles in association with the decomposition of iron acetylacetonate.

scholarly journals Bottom-Up Synthesis of Porous NiMo Alloy for Hydrogen Evolution Reaction

2017 ◽  
Author(s):  
Kailong Hu ◽  
Samuel Jeong ◽  
Mitsuru Wakisaka ◽  
Jun-ichi Fujita ◽  
Yoshikazu Ito
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Production ◽  
Water Splitting ◽  
Hydrogen Evolution Reaction ◽  
Annealing Temperature ◽  
Hydrogen Atmosphere ◽  
Porous Electrodes ◽  
Bottom Up ◽  
Annealing Temperatures ◽  
Oxide Phases

Bottom-up synthesis of porous NiMo alloy reduced by NiMoO4 nanofibers was systematically investigated to fabricate non-noble metal porous electrodes for hydrogen production. The different annealing temperatures of NiMoO4 nanofibers under hydrogen atmosphere reveal that the 950 °C annealing temperature is a key to produce bicontinuous and monorhinic porous NiMo alloy without oxide phases. The porous NiMo alloy as cathodes in electrical water splitting demonstrates not only almost identical catalytic activity with commercial Pt/C, but also superb stability for 12 days.

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