Search results for "Nanostructured Materials"
showing 10 items of 41 documents
Nanostructured Materials Obtained by Electrochemical Methods: From Fabrication to Application in Sensing, Energy Conversion, and Storage
2020
It is well known that physical and surface properties of nanomaterials are promising to enhance efficiency of nanostructured devices for sensing and for sustainable energy production, conversion, and storage. However, the practical use of nanomaterials is often complicated by the lack of scalable and cost-efficient synthesis procedures and the challenge of integrating into devices 1D nanomaterials saving their structural features. In this field, one of the most severe challenges is to find suitable methods for fabricating nanomaterials. Over the years, numerous preparation methods were proposed in the literature, but not all of them are easily scalable and economically advantageous for indu…
Nanostructured Electrochemical Devices for Sensing, Energy Conversion and Storage
2016
Nanostructured materials are attracting growing interest for improving performance of devices and systems of large technological interest. In this work, the principal results about the use of nanostructured materials in the field of electrochemical energy storage, electrochemical water splitting, and electrochemical sensing are presented. Nanostructures were fabricated with two different techniques. One of these was the electrodeposition of the desired material inside the channels of a porous support acting as template. The other one was based on displacement reaction induced by galvanic contact between metals with different electrochemical nobility. In the present work, a commercial polyca…
The origin of slow electron recombination processes in dye-sensitized solar cells with alumina barrier coatings
2004
We investigate the effect of a thin alumina coating of nanocrystalline TiO2 films on recombination dynamics of dye-sensitized solar cells. Both coated and uncoated cells were measured by a combination of techniques: transient absorption spectroscopy, electrochemical impedance spectroscopy, and open-circuit voltage decay. It is found that the alumina barrier reduces the recombination of photoinjected electrons to both dye cations and the oxidized redox couple. It is proposed that this observed retardation can be attributed primarily to two effects: almost complete passivation of surface trap states in TiO2 that are able to inject electrons to acceptor species, and slowing down by a factor of…
A hybrid nano-MOF/polymer material for trace analysis of fluoroquinolones in complex matrices at microscale by on-line solid-phase extraction capilla…
2021
Abstract A hybrid material (nano-metal organic framework@organic polymer, named as nano-MOF@polymer) was applied for the first time as sorbent for on-line solid-phase extraction capillary electrophoresis with ultraviolet detection (SPE-CE-UV). The resulting material was prepared building layer-by-layer a HKUST-1 (Hong Kong University of Science and Technology-1) nano-MOF onto the polymer surface, which allowed controlling the thickness and maximizing the active surface area. The sorbent was widely characterized at micro- and nano-scale to validate the synthesis and to establish the material properties. Then, fritless microcartridges (2 mm) were assembled by packing only a few micrograms of …
Fabrication and characterization of ZnO nanowires/CdSe/CuSCN eta-solar cell
2006
Des cellules solaires extremely thin absorber (eta) ZnO/CdSe/CuSCN a base de nanofils de ZnO ont ete realisees avec succes en utilisant des techniques faciles d'acces de depot en solution et par voie electrochimique. Une couche constituee de nanofils de ZnO monocristallin de plusieurs microns de hauteur et de 100-200 nm de diametre a ete deposee sur un substrat de verre conducteur (SnO 2 :F) recouvert d'une couche de ZnO formee par pyrolyse de spray agissant comme couche electronique bloquante. Une couche mince de 30-40 nm de CdSe jouant le role d'un absorbeur a ete electrodeposee de maniere conforme le long des nanofils de ZnO. Les espaces entre les nanofils composite de ZnO/CdSe ont ete r…
Electrochemical Synthesis of Zinc Oxide Nanostructures on Flexible Substrate and Application as an Electrochemical Immunoglobulin-G Immunosensor
2022
Immunoglobulin G (IgG), a type of antibody, represents approximately 75% of serum antibodies in humans, and is the most common type of antibody found in blood circulation. Consequently, the development of simple, fast and reliable systems for IgG detection, which can be achieved using electrochemical sandwich-type immunosensors, is of considerable interest. In this study we have developed an immunosensor for human (H)-IgG using an inexpensive and very simple fabrication method based on ZnO nanorods (NRs) obtained through the electrodeposition of ZnO. The ZnO NRs were treated by electrodepositing a layer of reduced graphene oxide (rGO) to ensure an easy immobilization of the antibodies. On I…
Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanopart…
2022
The advancement of analytical methods for nanoparticle measurements is critical both for the growing industrial exploitation of engineered nanoparticles and for developing robust strategies to understand and control the concentration of nanomaterials in humans and the environment. For high value nanoparticles, the measurement of nanoparticle number concentration in a liquid directly impacts the ability to assess the scale and reproducibility of the production process, it allows optimisation of efficiency and supports regulatory compliance. This measurement is also useful to monitor and control the intentional or accidental release of engineered nanoparticles into the environment at the produc…
Quantum wire with periodic serial structure
1991
Electron wave motion in a quantum wire with periodic structure is treated by direct solution of the Schr\"odinger equation as a mode-matching problem. Our method is particularly useful for a wire consisting of several distinct units, where the total transfer matrix for wave propagation is just the product of those for its basic units. It is generally applicable to any linearly connected serial device, and it can be implemented on a small computer. The one-dimensional mesoscopic crystal recently considered by Ulloa, Casta\~no, and Kirczenow [Phys. Rev. B 41, 12 350 (1990)] is discussed with our method, and is shown to be a strictly one-dimensional problem. Electron motion in the multiple-stu…
Suivi par diffraction de rayons X “in situ” de l'évolution du paramètre de maille du ferrite nanométrique γ-Fe2O3lors de l'isotherme d'adsorption d'e…
2002
La methode de synthese par chimie douce a ete utilisee pour synthetiser des nanoparticules de maghemite γ-Fe 2 O 3 dans une gamme de taille allant de 9 a 14 nm. Ces poudres, parfaitement cristallisees en phase spinelle, exemptes d'impuretes, avec une stoechiometrie en oxygene parfaitement controlee, ont servi de materiaux modeles pour cette etude. Le parametre de maille de ce materiau (0,8346 nm) s'avere etre non dependant de la taille. Cependant, le suivi en Diffraction de Rayons X in-situ revele des variations de ce parametre avec la modification de la surface en presence de vapeur d'eau. Les phenomenes de chimisorption et de physisorption jouent un role preponderant dans les evolutions o…
Review on the Processing and Properties of Polymer Nanocomposites and Nanocoatings and Their Applications in the Packaging, Automotive and Solar Ener…
2017
For the last decades, nanocomposites materials have been widely studied in the scientific literature as they provide substantial properties enhancements, even at low nanoparticles content. Their performance depends on a number of parameters but the nanoparticles dispersion and distribution state remains the key challenge in order to obtain the full nanocomposites’ potential in terms of, e.g., flame retardance, mechanical, barrier and thermal properties, etc., that would allow extending their use in the industry. While the amount of existing research and indeed review papers regarding the formulation of nanocomposites is already significant, after listing the most common applications, this r…