Nowadays, large-scale production of clean energy from renewable sources is needed to satisfy the growing global energy demand and replace CO2-polluting fossil fuels. In this scenario, solar energy is one of the most promising sources of energy, as it is an ideal C-neutral energy which can promote the electrolysis of water into oxygen and hydrogen. The hydrogen fuel generated in this way is named as ‘‘solar fuel’’. The hardest step in the water splitting process is the oxidation of water into protons and oxygen. Therefore, the development of catalysts that improve the results in the water oxidation catalysis (WOC) is essential. Research on water splitting catalysis has been conducted under two major perspectives: molecular and heterogeneous catalysis. A large part of the most active homogeneous catalysts in WOC are based on ruthenium and iridium complexes containing N-heterocyclic carbene ligands. It is well known that one of the main difficulties with homogeneous catalysts is their stability and recyclability. To solve it, new strategies consistent on the covalent attachment of the molecular organometallic complexes to solid surfaces, such as graphene oxides or carbon nanotubes, are being studied. Our group has previously synthesized several organometallic complexes containing NHC ligands that have shown good water splitting activity. In this work, we are looking to build water soluble iridium-NHC complexes in order to increase their solubility in water and so, improve their catalytic activity. On the other hand, the support of the complexes on thermally reduced graphene (TRGO) is reported. Finally, the catalytic activity for water splitting of all the synthesized complexes has been tested using CAN as sacrificial oxidant.

Resumen del póster presentado a la XXXVIII Reunión Bienal de la Real Sociedad Española de Química, celebrada en el Palacio de Congresos de Granada, del 27 de junio al 30 de junio de 2022.

Peer reviewed