Biomimetic Materials for Hydrogen Production

The urgency for new clean technologies for producing renewable fuels has put hydrogen production via photocatalysis and photoelectrochemical (PEC) processes as a promising clean technology. Despite all the advances in the development of new systems for hydrogen evolution from water using different hydrogenases with different photosensitizers and semiconductors, there remain a lot of opportunities and questions to be answered to create new and more efficient systems for hydrogen evolution through water splitting via PEC and understand better their mechanism. This work presents the results obtained in the study of a new biomimetic hybrid photocatalytic system for hydrogen production composed of a highly efficient visible light-absorbing copper complex as photosensitiser (PS) linked to a semiconductor (SC) surface, using a [FeFe] hydrogenase mimic complex as a catalyst for hydrogen production from water splitting via PEC. The newly sensitized hydrogenase mimic FeFe complex Fe2(dpet)(CO)6 was studied in chapter 3 which describes the photophysical and photoelectrochemical characterization and confirms its efficiency as a co-catalyst for proton reduction. The results shown in chapter 4 confirmed that the use of dopants such as Cu and Ni could tune the SC's energy bands, making it suitable for electron transfer (ET) from the PS. Chapter 5, describes the synthesis and characterization of a new Cu complex and proposes it is used as PS in photoanodes. Moreover, this application was studied in chapter 6 where it is confirmed that the use of the Cu complex [Cu(xantphos)(biq-COOH)]+ is possible and meets the requirements for its application as PS decreasing the recombination processes on the SC and proposed its application on hydrogen evolution via PEC.