Nanocrystalline Electrodes for (Solar) Photoelectrochemical Water Splitting

Photoelectrochemical (PEC) Tandem Cells with anodes and cathodes both of which are consisting of suitable semiconducting materials ensuring watersplitting into molecular oxygen and hydrogen, respectively, upon solar illumination are ideally suited for the conversion and storage of solar energy. Employing materials with sufficient abundance such as hematite (iron oxide) and pyrite (iron sulphide) n- and p-doped crystalline nanoparticles with suitable bandgap energies and band positions shall be synthesized employing wet chemical bottom-up methods and bandgap engineering, i.e., utilizing the quantum size effect. Sol/Gel synthesis methods will then be used to prepare the respective photoanodes and -cathodes for the PEC cells. While the overall performance of these cells will be investigated under (simulated) solar illumination, the project will focus on a detailed understanding of the involved individual reaction steps at both photoelectrodes. The latter processes will be studied combining suitable (photo)electrochemical analysis with time-resolved techniques (e.g., laser flash photolysis) and spatially resolved spectroscopic methods (e.g., ATR-FTIR spectroscopy). It is another important target of this project to develop – in close collaboration with other teams of the HSN – suitable models to describe the processes involved thus enabling the development of scale-up PEC assemblies for the anticipated industrial utilization.