A Sol-Gel Route for the Preparation of Co3O4 Catalyst for Oxygen Electrocatalysis in Alkaline Medium

“…14,15 In recent years, the increasing interest has been focused on the synthesis of Co 3 O 4 nanostructures because of the influences of particle size on their properties and applications. [16][17][18][19][20][21][22][23][24][25][26] Various wetchemical methods such as hydro-/solvothermal method, 27,28 combustion method, [29][30][31] microwave heating, [32][33][34] sol-gel process, 35 spray pyrolysis, 36 sonochemical method, 37 co-precipitation, 38 ionic liquid-assisted method, 39 polyol method 40 and a non-aqueous route 41 have been reported to synthesize Co 3 O 4 nanostructures. Nevertheless, most of these methods involve complex processes, high calcination temperatures, and expensive and toxic precursors.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Cobalt Oxide Nanoparticles Prepared by the Thermal Decomposition

Farhadi¹,

Javanmard²,

Nadri³

2016

ACSi

162

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In this work, thermal decomposition of the [Co(NH 3 ) 5 (H 2 O)](NO 3 ) 3 precursor complex was investigated under solid state conditions. Thermal analysis (TG/DTA) showed that the complex was easily decomposed into the Co 3 O 4 nanoparticles at low temperature (175 °C) without using any expensive and toxic solvent or a complicated equipment. The obtained product was identified by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). Optical and magnetic properties of the products were studied by UV-visible spectroscopy and a vibrating sample magnetometer (VSM), respectively. FT-IR, XRD and EDX analyses confirmed the formation of highly pure spinel-type Co 3 O 4 phase with cubic structure. SEM and TEM images showed that the Co 3 O 4 nanoparticles have a sphere-like morphology with an average size of 17.5 nm. The optical absorption spectrum of the Co 3 O 4 nanoparticles showed two band gaps of 2.20 and 3.45 eV, which in turn confirmed the semiconducting properties. The magnetic measurement showed a weak ferromagnetic order at room temperature. Photocatalytic degradation of methylene blue (MB) demonstrated that the as-prepared Co 3 O 4 nanoparticles have good photocatalytic activity under visible-light irradiation.

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“…Co 3 O 4 is an important magnetic p-type semiconductor, which belongs to the normal spinel crystal structure based on a cubic close packing array of oxide ions, in which Co(II) ions occupy the tetrahedral 8a sites and Co(III) ions occupy the octahedral 16d sites [15]. Extensive work has been done on preparation of Co 3 O 4 nanoparticles, including sol-gel [16,17], reduction/oxidation route [18], thermal decomposition [19,20], metal organic chemical vapor deposition (MOCVD) [21][22][23], chemical spray pyrolysis [24,25] etc. Previously, Co 3 O 4 nanoparticles with various morphologies have been synthesized [26,27].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Co3O4 nanoparticles by oxidation-reduction method and its magnetic characterization

et al. 2009

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Without any surfactant, antiferromagnetic Co 3 O 4 nanoparticles were synthesized successfully for the first time by means of an oxidation-reduction method with cobalt sulfate as starting material, which was oxidized to cobalt salt by NaNO 3 after alkalinizing with NaOH. Morphological, structural, spectroscopic and magnetic characterization of the product were done by SEM, TEM, XRD, and VSM, respectively. The average crystallite size (on the base of line profile fitting method), D and σ, is estimated as 30 ± 6 nm. Some anomalous magnetic properties and their enhanced effect have been observed in Co 3 O 4 antiferromagnetic nanocrystallites, including a bias field, coercivity, permanent magnetic moments and an open loop. These phenomena are attributed to the unidirectional anisotropy which is caused by the exchange coupling between AFM and FM layers, the existence of the spin glass like surface spins of Co 3 O 4 nanoparticles due to size effects and surface-area effect.© Versita Warsaw and Springer-Verlag Berlin Heidelberg.

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A Sol-Gel Route for the Preparation of Co3O4 Catalyst for Oxygen Electrocatalysis in Alkaline Medium

Cited by 180 publications

References 0 publications

A Sol–Gel Route for the Synthesis of Bi2Ru2O7 Pyrochlore Oxide for Oxygen Reaction in Alkaline Medium

A Sol–Gel Route for the Synthesis of Bi2Ru2O7 Pyrochlore Oxide for Oxygen Reaction in Alkaline Medium

Characterization of Cobalt Oxide Nanoparticles Prepared by the Thermal Decomposition

Synthesis of Co3O4 nanoparticles by oxidation-reduction method and its magnetic characterization

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