Défense de thèse de doctorat en sciences chimiques - Silvia PUGLIESE
Towards artificial photosynthesis: heterogenized molecular complexes for CO2 electroreduction and optimization of perovskite solar cells
Date : 25/04/2022 14:00 - 25/04/2022 17:00
Lieu : CH12
Orateur(s) : Silvia PUGLIESE
Organisateur(s) : Bao-Lian SU
Jury
- Prof. Robert SPORKEN (doyen de la faculté des sciences, UNamur), président
- Prof. Bao-Lian SU (département de chimie, UNamur), promoteur et secrétaire
- Prof. Marc FONTECAVE (laboratoire de chimie des processus biologiques, Collège de France), promoteur
- Dr Luca FUSARO (département de chimie, UNamur)
- Prof. Yann GARCIA (Institute of condensed matter and nanosciences, UCLouvain)
- Prof. Christel LABERTY-ROBERT (laboratoire de chimie de la matière condensée de Paris Tour, Sorbonne Université CNRS)
- Prof. Antoni LLOBET (Artificial photosynthesis group, Catalan institute for chemical investigation)
- Dr Elodie ANXOLABÉHÈRE (laboratoire d’électrochimie moléculaire, Université de Paris Cité)
- Prof. Damien DEBECKER (MOST, UCLouvain)
Abstract
The field of artificial photosynthesis, in which solar light is the driving force for the conversion of CO2 and H2O to chemical fuels, was pioneered by the work of Fujishima and Honda in the 70s; thereafter, it has been largely dominated by research on the reduction of water into hydrogen and its oxidation into oxygen. Despite its thermodynamic and kinetic challenges, the research on solar-powered CO2 reduction devices has increased, in parallel to the development of selective and efficient catalysts.
The first objective of the present project was to obtain CO2-reducing molecular catalysts in pure and active form and to integrate these catalysts into nanostructured porous electrodes, to be used in an electrolyzer. In order to immobilize a Ni(cyclam) complex on the surface of an electrode, two new cyclam derivatives bearing a pyrene substitution were synthesized. The complexes were found to be very active in the immobilized form, with faradic efficiencies for CO production exceeding 90% and current densities up to 10 mA.cm-2 in an acetonitrile/water mixture. Furthermore, for one of the two new complexes, the hybrid electrodes maintained the selectivity for CO in water, with the highest Faradaic Efficiency (87%) obtained at -0.8 V vs. RHE and current density around 6 mA cm-2.
The second objective of this project, in collaboration with the Swiss company Solaronix, was to improve the power conversion efficiency (PCE) of fully printable carbon-based perovskite solar cells (PSCs). Different degrees of porosity were introduced into nanoparticle-based TiO2 scaffolds, using polymer nanospheres as sacrificial structure, by varying the nature of the polymer, the diameter of the nanosphere and the polymer/TiO2 weight ratio. The addition of 5 wt% of 300 nm polystyrene nanospheres allowed to obtain an optimized layer for which the PCE max reached 13.6%, thus confirming a strategy that has the potential to afford excellent PCE enhancements with minimum impact on the manufacturing process of printable monolithic carbon-based PSCs, a front runner on the market for its competitive low cost.
Link
Télecharger :
vCal