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Walcarius A.,CNRS Laboratory of Physical Chemistry and Microbiology for the Environment
TrAC - Trends in Analytical Chemistry | Year: 2012

The past few years have seen an explosion in the use of ordered mesoporous carbon and, to lesser extent, templated macroporous carbon, as novel materials to design nanostructured electrodes devoted to sensing and biosensing. These materials offer attractive features that can be exploited in electrochemistry [e.g., good electronic conductivity, great porosity (high specific surface area, large pore volume and size) and widely open ordered structure]. After a brief presentation of these materials (template synthesis, characterization, properties and uses) and the ways to attach them to electrode surfaces (including their basic electrochemical behavior), we review their interest for electroanalytical purposes. We pay particular attention to applications in the fields of preconcentration electroanalysis, electrocatalysis, potentiometry and electrochemical biosensing, and to discussing the advantages of such templated porous carbons over other related nanostructured carbon materials. © 2012 Elsevier Ltd. Source


Walcarius A.,CNRS Laboratory of Physical Chemistry and Microbiology for the Environment
Electroanalysis | Year: 2015

A review (350 references) is given to the interest of mesoporous materials for designing electrochemical sensors. After a brief summary of the implication of template-based ordered mesoporous materials in electrochemical science, the various types of inorganic and organic-inorganic hybrid mesostructures used to date in electroanalysis and the corresponding electrode configurations are described. The various sensor applications are then discussed on the basis of comprehensive tables and some representative illustrations. The main detection schemes developed in the field are (volt)amperometric sensing subsequent to preconcentration and electrocatalytic detection. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Walcarius A.,CNRS Laboratory of Physical Chemistry and Microbiology for the Environment
Analytical and Bioanalytical Chemistry | Year: 2010

Nano- and/or macrostructuring of electrode surfaces has recently emerged as a powerful method of improving the performances of electrochemical devices by enhancing both molecular accessibility and rapid mass transport via diffusion, by increasing the electroactive surface area in comparison to the geometric one, and/or by providing confinement platforms for hosting suitable reagents. This brief overview highlights how template technology offers advantages in terms of designing new types of porous electrodes-mostly based on thin films, and functionalized or not-and discusses their use in analytical chemistry via some recent examples from the literature on electrochemical sensors and biosensors. © 2009 Springer-Verlag. Source


Hanna K.,CNRS Laboratory of Physical Chemistry and Microbiology for the Environment | Boily J.-F.,Umea University
Environmental Science and Technology | Year: 2010

While the transport of low molecular weight organic acids was widely investigated, little is known about the mobility of the carboxylated aromatic compounds containing double rings in natural porous media. This study combines macroscopic (batch and column), microscropic (vibration spectroscopy), and surface complexation modeling to evaluate the mobility of two PAH degradation products: naphthoic acid (1-naphthoic acid (NA) and 1-hydroxy-2-naphthoic acid (HNA)), in porous media consisting of goethite-coated sand. The loss of ligands from aqueous solution was attributed to (1) a hydrogen-bonded surface complex present over the entire 3-10 pH range as well as protonated (2) surface and (3) bulk precipitates below pH 5. Mobility in column experiments was strongly affected by ligand functionality. Adsorption breakthrough predictions that make use of surface complexation parameters accurately predicted NA mobility. Those for HNA however predicted much less adsorption reactions than in the batch sorption experiments. Additional breakthrough experiments and test calculations confirmed that these differences were not related to sorption kinetics. HNA adsorption breakthrough data could only be predicted by lowering intrinsic complexation constant of the formation of hydrogen-bonded species, thereby suggesting modifications of the diffuse layer properties under flow conditions. These findings have strong implications in the assessment and prediction of contaminant transport and environmental remediation. © 2010 American Chemical Society. Source


Walcarius A.,CNRS Laboratory of Physical Chemistry and Microbiology for the Environment
Chemical Society Reviews | Year: 2013

Ordered mesoporous materials prepared by the template route have attracted increasing interest from the electrochemists community due to their plenty of unique properties and functionalities that can be effectively exploited in electrochemical devices. This review will cover the whole field of the intersection between electrochemistry and ordered mesoporous materials. The latter are either electronically insulating (silica and some other metal oxides, as well as silica-based organic-inorganic hybrid materials), semi-conducting (metal oxides), or conducting (metals, carbons). The three main intersection areas are: (1) the development/use of electrochemical methods to characterize the properties of mesoporous materials (i.e., charge and mass transfer processes); (2) the generation of mesostructured solids by electro-assisted deposition using appropriate templates; and (3) the application of these novel materials for electrochemical purposes. The most common devices to date are based on a bulk composite or thin film configuration and the resulting electrodes modified with such mesoporous materials have been successfully applied in various fields, including mainly electrochemical sensing and biosensing as well as energy conversion and storage (620 references). © The Royal Society of Chemistry 2013. Source

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