Organic Materials on Surfaces for (Photo)Activated Reactions

Tackling the consequences of climate change, particularly its adverse effects on the environment, requires a collective effort. One of the problems related to climate change is the indiscriminate use and/or poor management of natural resources. While fossil fuels have been the primary source used in key sectors such as energy or polymer industry, other renewable sources, such as sunlight, have been overlooked for many years. Fortunately, with the rapid development of solar panels and photovoltaic science and technology, in particular, society is becoming increasingly aware of the power of this inexhaustible energy source. A clear conclusion of our current dependence on fossil fuels is that a new paradigm is necessary. Green hydrogen or carbon dioxide capture, and transformation technologies have been identified as key vectors that must contribute to the development of a more sustainable society. In this context, the objective of SUPERXFO is to develop photocatalytic systems active in the water reduction reaction to generate hydrogen and the activation of carbon dioxide to generate ethylene or ethanol, using affordable, low-cost materials and with no significant carbon footprint associated with the processes. Specifically, SUPERXFO will develop two-dimensional covalent organic frameworks (2D-COFs) specifically designed to be deposited on conductive surfaces to generate electrodes and photoelectrodes capable of triggering surface chemical reactions, using sunlight as the main energy source. To achieve this, the project addresses two major challenges: (i) modulation of the electronic properties of the (semi)conductive material and (ii) formation of homogeneous thin films with controlled thickness. Through the rational design of the materials chemical structure, the aim is not only to improve its light absorption and charge separation capabilities by introducing electron-donor and acceptor groups but also to enhance its capacity to form inks suitable for electrode preparation. Direct synthesis and post-functionalization methods of 2D-COFs will be used, the latter also enabling the introduction of catalytic centers into the (semi)conductive structure. These catalytic centers increase the production rate of products (hydrogen, ethylene, or ethanol), resulting in greater efficiency of the overall process. The new materials will be used in formulation mixtures together with other additives to produce suitable inks, which will be employed to fabricate (photo)electrodes using scalable deposition methods, with the ultimate goal of generating a light-powered device. Finally, SUPERXFO aims to adapt this technology, at a proof of concept level, to the production of other industrially relevant chemicals, such as pharmaceuticals or agrochemicals, through synthetic methods involving redox-type reactions, an underexplored field that can adopt many of the principles used in hydrogen generation from water. The electrodes and devices derived from SUPERXFO will consist mainly of organic material (mostly carbon and hydrogen), with only a small proportion of metal corresponding to the catalytic centers and avoiding the use of precious metals. Overall, an affordable cost is expected to make the scaling and implementation of this technology feasible.