Tandem photoelectrochemical cells for solar driven carbon dioxide reduction and alcohol oxidation – PECALO

The objective will be attained thanks to the combination of highly active CO2 reduction molecular catalysts made of earth abundant 3d transition metal complexes, the use of very efficient copper chalcogenide (CuInxGa1-xSe2: CIGS) based photocathodes, a photoanode composed of amorphous silicon layer functionalized with nitroxyde based catalysts.

Only after one year of program work, we were able to double the initial performance of photo-reduction of CO2 into CO relative those when the project starts and we demonstrate the relevance of the association of the hydrogenated amorphous silicon semiconductor with a catalyst based on nitroxide to oxidize benzyl alcohol.

The short-term objective is to further amplify the photoelectrocatalytic performances of CO2 reduction and oxidation of alcohols thanks to an optimization of the photoelectrodes and the catalysts grafted on their surfaces.

The work gave rise to one publication and 2 conferences in congresses.

Artificial photosynthesis is a key research field, because it will have a huge beneficial impact on a future post-carbon energy area. In this project, we propose to develop, for the first time, a stable tandem photoelectrochemical to reduce CO2 to CO with concomitant oxidation of alcohols in carbonyls compounds, thereby providing a strategy for generating economically valuable products at both electrodes with sunlight. At the end of the project, the cell will have a high solar to chemical energy efficiency (3%) with an outstanding stability (100 h).
This ambitious objective will be attained thanks to the combination of highly active CO2 reduction molecular catalysts made of earth abundant 3d transition metal complexes, the use of very efficient copper chalcogenide (CuInxGa1-xSe2: CIGS) based photocathodes, a photoanode composed of amorphous silicon layer functionalized with nitroxyde based catalysts and a new cross-linking strategy to stabilize the catalysts on the electrode. The project gathers four teams: CEISAM and IMN at Nantes University and LEM at at University Paris and LPICM at Ecole Polytechnique at Saclay with recognized specialists in six major areas such as CuInxGa1-xSe2 and amorphous silicon based semiconductors, solid state chemistry, organic synthesis, coordination and inorganic chemistry, electro- and photo-electrocatalysis.