Search results for "Iron oxide"
showing 10 items of 114 documents
Influence of electrolyte temperature on the synthesis of iron oxide nanostructures by electrochemical anodization for water splitting
2018
[EN] Iron oxide nanostructures are an attractive option for being used as photocatalyst in photoelectrochemical applications such as water splitting for hydrogen production. Nanostructures can be obtained by different techniques, and electrochemical anodization is one of the simplest methods which allows high control of the obtained morphology by controlling its different operational parameters. In the present study, the influence of the electrolyte temperature during electrochemical anodization under stagnant and hydrodynamic conditions was evaluated. Temperature considerably affected the morphology of the obtained nanostructures and their photoelectrochemical behavior. Several techniques …
How does anodization time affect morphological and photocatalytic properties of iron oxide nanostructures?
2020
Abstract Iron oxide nanostructures are promising materials to be used as photocatalysts in different photoelectrochemical applications. There are different techniques in order to synthesize these nanostructures, but one of the most inexpensive and simple method is electrochemical anodization. This method can lead to different nanostructures by controlling its parameters. Anodization time is one of the most critical parameters since it considerably affects the properties of the obtained nanostructures. In this work, different anodization times (5, 10, 15, 30 and 60 min) were studied. The resulting nanotubes were characterized by field emission scanning electron microscopy, Raman laser confoc…
Flash microwave synthesis of trevorite nanoparticles.
2008
Nickel ferrite nanoparticles have several possible applications as cathode materials for rechargeable batteries, named 'lithium-ion' batteries. In this study, NiFe{sub 2}O{sub 4} was prepared by microwave induced thermohydrolysis. The obtained nanoparticles were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), BET method, transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS). All the results show that the microwave one-step flash synthesis leads in a very short time to NiFe{sub 2}O{sub 4} nanoparticles with elementary particles size close to 4-5 nm, and high specific surfaces (close to 240 m…
Synthesis of Titanate Nanotubes Directly Coated with USPIO in Hydrothermal Conditions: A New Detectable Nanocarrier
2011
International audience; Abstract: For the first time, titanate nanotubes (TiONts) coated with USPIO (ultrasmall superparamagnetic iron oxide) without polymer functionalization and directly obtained during TiONts formation is reported. The coating of these tubes was performed directly during the TiONts hydrothermal synthesis. After this treatment, in strongly basic conditions, USPIO particles kept their structure and magnetic properties while their size distribution slightly increased. By coupling zeta-potential measurements and TEM observations at different pH it appeared that interactions between nanotubes and USPIO were not electrostatic. This study presents the new design of a titanate n…
The key role of nanocasting in gold-based Fe2 O3 nanocasted catalysts for oxygen activation at the metal-support interface
2019
5 Tablas.- 10 Figuras.- This is the peer reviewed version of the following article: The key role of nanocasting in gold‐based Fe2O3 nanocasted catalysts for oxygen activation at the metal‐support interface, ChemCatChem 11: 1915-1927 (2019), which has been published in final form at http://dx.doi.org/10.1002/cctc.201900210. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.
Contactless Nanoparticle-Based Guiding of Cells by Controllable Magnetic Fields
2021
Peter Blümler,1 Ralf P Friedrich,2 Jorge Pereira,3 Olga Baun,1 Christoph Alexiou,2 Volker Mailänder3,4 1Institute of Physics, Johannes Gutenberg-University Mainz, Mainz, 55128, Germany; 2Department of Otorhinolaryngology, Head and Neck Surgery, Section of Experimental Oncology and Nanomedicine (SEON), Else Kröner-Fresenius-Stiftung-Professorship, Universitätsklinikum Erlangen, Erlangen, 91054, Germany; 3Department of Physical Chemistry, Max Planck Institute for Polymer Research, Mainz, 55128, Germany; 4Department of Dermatology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, 55131, GermanyCorrespondence: Peter Blümle…
Effect of precursor concentration on size evolution of iron oxide nanoparticles
2017
Thermal decomposition is a promising route for the synthesis of magnetic nanoparticles. The simplicity of the synthesis method is counterbalanced by the complex chemistry of the system such as precursor decomposition and surfactant–reducing agent interactions. Control over nanoparticle size is achieved by adjusting the reaction parameters, namely, the precursor concentration. The results, however, are conflicting as both an increase and a decrease in nanoparticle size, as a function of increasing concentration, have been reported. Here, we address the issue of size-controlled synthesis via the precursor concentration. We synthesized iron oxide nanoparticles with sizes from 6 nm to 24 nm wit…
Silica-coated superparamagnetic nanoparticles as contrast agent for magnetic resonance imaging: Synthesis and physicological charaterizations
2015
Superparamagnetic iron oxide nanoparticles (SPIONs) have received a growing interest for various biomedical applications due to their interesting magnetic properties. Herein, we report a method for facile synthesis of colloidal silica-coated superparamagnetic iron oxide nanoparticles (Si-SPIONs). The polyvinyl alcohol (PVA)-SPIONs were successfully prepared and then coated with silica by the modified Stober method. The obtained Si-SPIONs are highly monodisperse with uniform morphology. Notably, comparing to uncoated SPIONs, silica coated ones show colloidal stability region at physiological pH which is applicable in biomedical applications and synthesis at the scale of grams was easily obta…
(Ag)Pd-Fe3O4 Nanocomposites as Novel Catalysts for Methane Partial Oxidation at Low Temperature
2020
Nanostructured composite materials based on noble mono-(Pd) or bi-metallic (Ag/Pd) particles supported on mixed iron oxides (II/III) with bulk magnetite structure (Fe3O4) have been developed in order to assess their potential for heterogeneous catalysis applications in methane partial oxidation. Advancing the direct transformation of methane into value-added chemicals is consensually accepted as the key to ensuring sustainable development in the forthcoming future. On the one hand, nanosized Fe3O4 particles with spherical morphology were synthesized by an aqueous-based reflux method employing different Fe (II)/Fe (III) molar ratios (2 or 4) and reflux temperatures (80, 95 or 110 °
Controlled hydrodynamic conditions on the formation of iron oxide nanostructures synthesized by electrochemical anodization: Effect of the electrode …
2017
[EN] Iron oxide nanostructures are of particular interest because they can be used as photocatalysts in water splitting due to their advantageous properties. Electrochemical anodization is one of the best techniques to synthesize nanostructures directly on the metal substrate (direct back contact). In the present study, a novel methodology consisting of the anodization of iron under hydrodynamic conditions is carried out in order to obtain mainly hematite (alpha-Fe2O3) nanostructures to be used as photocatalysts for photoelectrochemical water splitting applications. Different rotation speeds were studied with the aim of evaluating the obtained nanostructures and determining the most attract…