2023 BIST Ignite Project: MOLOPEC

Molecular Catalysts to Enable Organic Photoelectrodes for Efficient Photoelectrochemical H₂ Production and CO₂ Reduction

Project overview

The MOLOPEC project contributes to the development of solar synthetic fuels as a sustainable solution for solar energy conversion, storage, and distribution.

Solar synthetic fuels, based on photoelectrochemical (PEC) water splitting for H2 and CO2 reduction hold promise for long-term storage and distribution of solar energy. Taking advantage of recent progress in organic photovoltaics (OPV) based in non-fullerene acceptors (NFAs), organic photoelectrodes (OPEC) employing the donor/acceptor PM6:Y6 system have recently been found to sustain competitive photocurrents (> 15 mA/cm2). The advantages of using these carbon-based and free-of-critical raw materials are the tuneable band gaps, semitransparency, and compatibility with flexible substrates, enabling lightweight devices that can be made by high-throughput roll-to-roll technologies. However, challenges such as self-oxidation in aqueous electrolytes and surface catalysis optimization need to be addressed.

To overcome these challenges, molecular water oxidation catalysts (WOC), molecular proton reduction catalysts (PRC), and molecular CO2 reduction catalysts (CO2RC) overlayers can serve as transparent, conductive, and chemically stable barriers. These molecular-catalyst overlayers inhibit direct contact between water and the donor/acceptor molecules if fabricated without damaging the PM6:Y6 blend.

The MOLOPEC project combines the expertise of ICFO and ICIQ in fabricating organic photoactive materials and molecular catalysts, respectively, with ICN2’s advanced characterization techniques capable of revealing sub-nanometric features of the organic materials. This collaboration aims to fabricate a highly productive and stable OPEC-OPV tandem system for bias-free H2 and CO2 reduction reactions. The goal is to overcome the limitations associated with inorganic metal oxide photoanodes and electrocatalysts in large-scale solar fuel production.