Thesis

Green production of dihydrogen (H2) is a potential solution to the current energy crisis. Photocatalytic water cracking produces dihydrogen and oxygen. However, electrocatalysts are required for efficient water separation (both in the H2 and O2 evolution reactions). To date, noble metal nanomaterials are the most efficient materials. However, these resources are not only scarce and expensive, but also unstable and prone to poisoning during electrochemical reactions. There is therefore an urgent need to develop low-cost, highly efficient and stable electrocatalysts for global water separation.

In this context, molybdenum (Mo)-based electrocatalyst materials hold great promise and are currently attracting growing interest in the energy sector. Our group has already demonstrated the possibility of obtaining large quantities of Mo carbides/carbon nanocomposites using water as a solvent and a safe, low-cost Mo oxide precursor with good catalytic activities. The project aims to explore new doped materials for enhanced electrochemical performance.

The aim is to synthesize doped molybdenum carbides or (oxy)nitrides as nanocomposites (directly mixed with graphitic carbon (GC)) on a large scale in a single step by laser pyrolysis, noted MoMX/GC (M: Ni, Co, Cu, Fe; X = C, N). The compounds will be characterized by X-ray diffraction and FTIR/Raman spectroscopy. Photocatalysis mechanisms will be studied, in particular by monitoring dihydrogen production in collaboration with the Institut des Sciences Chimiques in Rennes.


Références
T. Caroff et al., Facile synthesis and characterization of molybdenum carbides/carbon nanocomposites by laser pyrolysis, Nanomanufacturing 2022, 2, 112.
Q. Wang et al., Particulate photocatalysts for light-driven water splitting: mechanisms, challenges, and design strategies, Chem. Rev. 2020, 120, 919.