A simple case of artificial photosynthesis is the splitting of water into molecular oxygen and hydrogen by the action of light. With this process, we can obtain solar fuels (e.g. hydrogen gas) from water and sunlight and it appears as a promising alternative to the traditional fossil fuels.
The objective of this thesis is the synthesis and study of cobalt catalysts active for the hydrogen evolution reaction (HER), as well as the preparation of electrodes and photoelectrodes active for HER and water oxidation to dioxygen reaction (WOR) with the lowest energy consumption.
In this direction, macrocyclic cobalt HER catalysts have been synthetized. Catalytic tests and mechanistic studies allowed us to identify the rate determining step of the reaction under electrochemical and photochemical conditions. In addition, electrodes containing graphene functionalized with a molecular HER catalyst have been prepared and thoroughly studied. Finally, photoanodes based on BiVO4 and photocathodes based on CZTSe active for WOR and HER respectively have been developed, in both cases working below the thermodynamic potential under sunlight illumination.