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Nombre de programmes trouvés : 1794
Conférences

le (27m19s)

Beatriz Avila - CO2 electroreduction to formate on Sn, Bi and Sb nanostructured electrodes: from fundamental studies to practical devices

The electrochemical reduction of CO2 into chemical products of interest has been considered as an interesting route not only to mitigate climate change but also to store renewable energy in the form of value-added chemicals. Among other possible chemicals, formic acid (HCOOH) or formate (HCOO−) (depending on pH value) is one of the most attractive carbon-based products due to its potential uses and its high world demand including its use as a fuel for low-temperature fuel cells and as a renewable hydrogen carrier molecule. In this contribution, we will summarize our most ...
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le (39m16s)

Joaquim Faria - Carbon geometries as the base concept for developing efficient photocatalysts

During the past several decades' new carbon allotropes have been accounted for and synthesised. Many notable breakthroughs include exciting works on synthesis, functionalisation, characterisation and applications of carbon nanotubes, graphene, and graphene-like structures, like graphitic carbon nitrides.   The exciting progress made since the initial use of carbons as modifiers of optical semiconductors has stimulated many types of research in different fields of the immediate and relevant application. Apart from the obvious applications in water treatment and remediation, there are compelling examples in photocatalytic synthesis, assisted conversion with the ...
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Conférences

le (34m20s)

Carlos Sanchez - Electrolyte engineering for electrochemical CO2 reduction

Ionic liquids (ILs) in electrocatalysis have attracted a lot of attention from the seminal work of Rosen et al. [1] where they achieved a relevant overpotential decrease for CO2 reduction reaction (CO2RR) on a silver electrode. Moreover, ILs have been proposed as organic promoters for enhancing the catalytic activity by modifying the electrostatic properties at the electrochemical interface. Then, electrolyte engineering has become a powerful way to impact on the stability of reaction intermediates and control reaction selectivity.   The role of different ILs as simultaneous supporting electrolyte and co-catalyst ...
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Conférences

le (40m21s)

Christel Laberty-Robert - Impact of Electrodes Nanostructuration on Photoelectrochemical Performances

Hydrogen is presented by some industrialists and managers as a potential pillar of the ecological transition, particularly in the context of transport (hydrogen-powered cars, hydrogen-powered trains, hydrogen-powered airplanes, etc.), the storage of energy from intermittent renewable sources or in industry (steel and chemical industries). Using hydrogen to decarbonize the economy only makes sense if it is produced in a decarbonized way. In this context, this talk will focus on hydrogen production from renewable sources, solar and water. The performance (absorption of light, creation of photo-charges, their migration and their reactivity with ...
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Conférences

le (40m8s)

José Solla-Gullon - Recent advances and remaining challenges on the use of shape-controlled-metal nanoparticles in Electrocatalysis

The incorporation of shape-controlled metal nanoparticles in Electrocatalysis is contributing significantly to a better understanding of the correlations between surface structure and electrochemical reactivity at the nanoscale [1,2]. In this communication, some of the basic requirements to properly use these shaped metal nanoparticles in electrochemical reactions including surface cleanness, and correlations between particle shape and surface structure will be reported. Then, some recent advances in the application of these shaped nanomaterials for different electrochemical reactions of interest will be highlighted [3-5]. Finally, some of the most important remaining challenges on this ...
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Conférences

le (23m56s)

Alejandro Anson-Casaos - Photoelectrochemical characterization of C/TiO2 and C/ZnO nanomaterials in aqueous electrolyte

Carbon nanostructures, including single-walled carbon nanotubes, reduced graphene oxide, and carbon dots, are inserted in TiO2 and ZnO photoanodes with the aim of improving their activity. For the electrode assembly, TiO2 or ZnO nanoparticles, as well as carbon nanomaterials, are dispersed in a liquid and deposited on FTO by spray coating. Various mixed and layer-by-layer electrode configurations are considered. As-prepared electrodes are evaluated by photoelectrochemical (PEC) techniques, mostly cyclic voltammetry and transient photocurrent measurements.   The insertion of the carbon component improves the photocurrent response depending on the measurement conditions, ...
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Conférences

le (36m38s)

Giuseppe Marci - Photocatalytic reduction of CO2 in gas-solid and in liquid-solid regimes

The increasing CO2 level in the atmosphere is a global environmental problem; therefore, the development of efficient catalytic processes for CO2 reduction is a challenge. Heterogeneous photo-catalysis is an attractive technology for this purpose. Literature reports that formic acid, methanale, methanol and methane can be formed by photocatalytic reduction of CO2. In this contribution, it will be showed that the CO2 reduction products and their distribution depend on several factors like the kind of photocatalyst and the presence of water vapor [1]. Moreover, the coupling of different photo-catalyst (GaP/TiO2) and the ...
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Conférences

le (35m2s)

Ally Aukaloo - From molecular to nanostructured materials for artificial photosynthesis

Inspired by chemical subtleties at the active sites of enzymes dealing with the CO2 management in our biosphere, we will discuss on how hydrogen bonding and electrostatic effects may thrive the catalytic power molecular catalysts.[1] Photosystem II is the only enzyme that can capture sunlight to extract electrons and protons from water that are expelled in the form of reduced quinones. We have developed nanostructured conjugated polymers that can act as photocatalysts to replicate the functions of Photosystem II.[2]   [1] P. Gotico ...
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Conférences

le (41m28s)

Olivier Joubert - Brief Overview of Current French Hydrogen Research Activities, Focus on Materials

Twenty years ago, the French scientific community working in the field of hydrogen, started to federate under the leadership of the CNRS. It took the form of successive Research Grouping (GdR) bringing together experts in solid oxide fuel cell (SOFC), proton exchange polymer membrane (PEMFC) fuel cells, hydrogen storage and systems mainly from CNRS but also from CEA. These GdRs promoted and structured an interdisciplinary field of research with excellent results.   Since January 1st of 2020, the CNRS community has formed the Research network on ...
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Conférences

le (38m38s)

Pascal Brault - Reactive molecular dynamics simulations of H2 production and conversion

Since H2 production and conversion efficiencies can be improved and monitored at the molecular scale, reactive molecular dynamics simulations (rMDS) are expected to be of great promise for understanding associated basic mechanisms. Basically, rMDS is a technique aiming at solving full trajectories of a set of atoms, molecules, nanoparticles, with the only ingredient of force fields driving interactions between relevant species.   Due to the recent growth of improved and reactive force fields such as ReaxFF and COMB3 families, it become possible to address complicated reactive process such as H2 ...
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