Personal web page : https://iramis.cea.fr/Phocea/Membres/Annuaire/index.php?uid=ppicot
Laboratory link : https://iramis.cea.fr/nimbe/lions/
Rising energy demand and the need to reduce the use of fossil fuels to limit global warming have created an urgent need for clean energy collection technologies. One interesting solution is to use solar energy to produce fuels. Low-cost materials such as semiconductors have been the focus of numerous studies for photocatalytic reactions. Among them, 1D nanostructures are promising because of their interesting properties (high and accessible specific surface areas, confined environments, long-distance electron transport and facilitated charge separation). Imogolite, a natural hollow nanotubes clay, belongs to this category. Its particularity does not lies in its chemical composition (Al, O and Si) but in its intrinsic curvature, which induces a permanent polarization of the wall, effectively separating photo-induced charges. This nanotube belongs to a family sharing the same local structure with different curved morphologies (nanosphere and nanotile). In addition, several modifications of these materials are possible (coupling with metal nanoparticles, functionalization of the internal cavity), enabling their properties to be modulated. These materials are therefore good candidates as nanoreactors for photocatalytic reactions. So far, proof of concept (i.e. nanoreactor for photocatalytic reactions) has only been obtained for the nanotube form. The aim of this thesis is therefore to study the whole family (nanotube, nanosphere and nanotile, with various functionalizations) as nanoreactors for proton and CO2 reduction reactions triggered under illumination.