SUN-SPOT - copper indium Sulfide qUaNtum dotS as Photocatalysts for sun-driven biomass OxidaTion

The SUN-SPOT project targets the solar-driven production of hydrogen from water reduction, coupled to biomass valorization to

obtain added value chemicals.

To this goal, SUN-SPOT proposes the design and synthesis of hybrid nanomaterials based on Copper Indium Sulfide Quantum Dots (CIS QDs) and molecular catalysts that can be incorporated as active elements in a photoelectrochemical cell aimed at the conversion and storage of solar energy into added-value chemicals and energy rich species (solar fuels). In order to achieve this innovative target, the project includes an in-depth study of the photophysical and electrochemical properties of the new hybrid nanomaterial and their components. This preliminary study will allow to acquire the knowledge to clarify the electronic coupling between the QD and the catalyst according to their characteristics and their functionalization.

The best performing subunits will be used for the preparation of appropriate photoanodes capable of producing, by oxidation of biomass derived species, added-value chemicals useful as building blocks for chemical industry. As a model compounds biomass alcohol derivatives will be used (e.g.: 5-hydroxymethylfurfural) due to the interest of polymer industry in the product of its oxidation, the 2,5-furandicarboxylic acid. At the same time, the cathodic compartment of the photoelectrochemical cell will feature carbon-based electrodes (e.g., nanohorn structures) functionalized with earth-abundant catalysts, such as Ni3S2, for the production of hydrogen by water reduction. The target efficiency of solar-to-chemical energy conversion is 4%, which represents the ratio between the chemical energy, stored in the produced hydrogen and oxidation product of biomass-derived alcohols, and the solar energy incident on the photoelectrochemical cell.

The SUN-SPOT proposal is thus expected to have a strong impact in the field of artificial photosynthesis, but also to significantly advance knowledge in the field of nanomaterial science, catalysis and electronic couplings within the investigated hybrid materials. Such an ambitious goal is made possible by a consortium constituted by three research units with long-standing collaboration and strong background in photochemistry, photoelectrochemistry and design/synthesis of nanomaterials and molecular catalysts.