One of the initial tasks of the project consisted on assembling an interdisciplinary team able to carry out the different research lines involved in the project: physicists, chemists and material scientists. This - together with the installation of new facilities and equipment - build up solid grounds for the development of the project. Three main aspects were covered along the project: a) the synthesis of new plasmonic catalysts; b) the mechanisms behind energy transfer at plasmonic interfaces and 3) new techniques capable of exploring and exploiting sunlight energy conversion at the nanoscale.
On one side, we mastered the synthesis of novel and complex plasmonic catalysts - either mono or bimetallic ones – and tested them towards sunlight-driven redox reactions, including hydrogen generation. As such, we have exploited and enhanced different properties by designing and synthetizing colloidal structures with internal hotspots, multiple hotspots or fractal character – among others - improving the light absorption and energy conversion capabilities of standard colloidal architectures. As a result of this part of the project, we achieved world-record efficiencies in sunlight-to-hydrogen conversion by using bimetallic plasmonic supercrystals, a new technology that captures direct sunlight and transfers the energy to reactants in order to generate hydrogen by catalyzing the reaction. These results received worldwide press cover, besides top publications and a patent.
Furthermore, we have explored different nanoscale phenomena taking place across the plasmonic metal – molecule interface. We described a new type of charge transfer process mediated by the electric double layer that surround plasmonic colloids. Moreover, by combining plasmonic colloids and electrochemical measurements, we reveled the energy of photoexcited electrons and holes in these systems and the impact of crystal facets of nanoparticles in these type of processes. This part of the project is also reflected in several top publications.
Finally, we developed new techniques for both: mapping nanoscale temperature at plasmonic interfaces and producing large-scale patterning of plasmonic colloidal catalysts. These techniques constitute a fundamental step towards optimizing and scaling-up our experimental results. In the same line, we developed another method to understand these processes at the single molecule level, by looking at reactive in-operando super resolution microscopy. All these results also constitute a large body of publications.
A s a summary, we were able to image, design, synthetize and test new hybrid plasmonic materials for efficient sunlight-to-fuels generation. The very successful development of the project lead to world-record materials for sustainable energy production and conversion, reflected in several publications, patents and wide media cover. With this project, we set the basis for a new route in the solar energy community by showcasing a new class of materials that will hopefully bridge us closer to a sustainable future.
