The first Work Package (WP1) regarded the development of (photo)cathodes, i.e. the optimization of the reduction site of the final (photo)electrochemical cell. The corresponding scientific objective (SO-1) was pursued in close conjunction to SO-3, since the preparation of the (photo)cathodes encompasses the in-depth analysis of their performances, employing the advanced photo- and electrochemical techniques described in Work Package 3 (WP3).
In particular, we identified the deposition of an ultrathin layer of titanium as an optimal protection strategy for p-type silicon electrodes, intended to be used as photocathodic platforms for the reduction of carbon dioxide. A scouting functionalization with platinum nanoparticles gave interesting results for the proton reduction to yield hydrogen, another clean alternative to fossil fuels, giving only water as the combustion product. These results were published on “Electrochimica Acta” (2018, 271, 472) and presented as an oral communication at the Spring Meeting of the European Materials Research Society (Strasbourg, 2017). Current efforts are directed towards the functionalization of the same interfaces with copper nanostructures, the selected catalytic domains for CO2 reduction. At the same time, we investigated alternative strategies using novel Au-nanoarchitectures, which turned out to be excellent cathodes, producing CO and H2, the major components of synthesis gas.
The second Work Package (WP2) regarded the development of photoanodes able to perform water oxidation at the anodic compartment of the final (photo)electrochemical cell. Also in this case, the corresponding scientific objective (SO-2) was pursued in close conjunction to SO-3. The main achievements were: (i) the preparation of optimized WO3 photoanodes displaying a BiVO4 overlayer to enhance visible light absorption. The further functionalization with a molecular ruthenium water oxidation catalyst led to an enhancement of the evolved oxygen. These results have been recently published on “Sustainable Energy & Fuels”; (ii) the preparation of different anodic interfaces exploiting the stacking of perylenic aggregates on wide band-gap oxides. Their characterization with advanced techniques was published on the “Journal of Physical Chemistry C” (2017, 121, 17737), as well as presented as a poster at the “2nd International Solar Fuels Conference” (San Diego, 2017) and as an oral communication at the “Italian Photochemistry Meeting” (Perugia, 2017); (iii) the optimization of hematite photoanodes via their functionalization with earth-abundant catalysts, able to boost water oxidation. We could evidence that the catalysts’ morphology is pivotal to yield enhanced performances. The results were published on “ACS Applied Materials and Interfaces” (2016, 8, 20003), as well as presented as a poster at the “NanoGe September Meeting on Solar Fuels” (Berlin, 2016) and at the “Joint Congress of the French and Italian Photochemists and Photobiologists” (Bari, 2016). In the latter case, I was awarded the poster prize and I gave a flash oral presentation. We further extended this study to different hematite/catalyst interfaces, and the corresponding manuscript is currently under preparation. Meanwhile the results were presented as a poster at the “NanoGe September Meeting on Solar Fuels” (Barcelona, 2017).
Furthermore, during the MSCA fellowship, I promoted the ARCADIA project participating to different outreach activities for students and the general public by means of presentations and experiments related to my activity.