Thèses

Lundi 15 Mars 2021 à 14h00.

Precursors-guided synthesis of upconverting nanomaterials for near-infrared driven photocatalysis

''The utilization of solar energy to solve environmental problems such as water detoxification, air purification and hydrogen production has attracted great interest from the scientific community over the last two decades. Solar photocatalysis is an interesting avenue to target all these environmental issues. Currently, technologies do not yet allow for the efficient use of a significant portion of the solar spectrum, namely the infrared, which corresponds to nearly ~48% of the total solar spectrum. This thesis aims at preparing nanocomposite materials that use these low energy solar photons by converting them into high energy UV and visible photons and then using them for classical photocatalysis. To achieve this, two major aspects of the preparation of this modified photocatalyst were emphasized. Firstly, the synthesis of materials that could efficiently convert currently unused photons and secondly, the preparation of their composite with TiO2, the most widely used photocatalyst.
This doctoral thesis focuses on an approach based on "upconversion" in order to extend the range of use of the solar spectrum. To achieve this goal, two optimization strategies were addressed. The optimization of the quantum efficiency of upconversion nanoparticles (UCNPs) using new anhydrous precursors and, the preparation of UCNPs-TiO2 nanocatalyst using metallogels and/or core-shell structures. Finally, we test the objective of using low energy infrared solar photons by performing photocatalysis under IR irradiation only using the platform developed in this work.

Directeurs de thèse/ thesis director : Dr. Gilles LEDOUX and Dr. Shashank MISHRA

Membres du jury / members of the jury:
HEMMER Eva (Ottawa, Canada)
DANTELLE Géraldine (Grenoble, France)
GOLDNER Philippe (Paris, France)
BLANCHARD Juliette (Paris, France)
PAROLA Stéphane (Lyon, France)

''