Spectroelectrochemically-enabled creation, control, and understanding of complex, highly ordered electrochemical interfaces

14/05/2026 to 13/05/2031

Electrochemical interfaces play an important role for applications in energy and matter conversion. The phase boundary between electrode and electrolyte determines properties such as charge-transfer, catalytic function, stability or charge-carrier recombination, yet its exact structural composition if often unknown. Especially for complex electrochemical interfaces, that show a high degree of reactivity with the electrolyte, also single-crystals form amorphous interphases, which impede the understanding of potential distributions or electronic interface states. In this Heisenberg-proposal, electrochemical reflection anisotropy spectroscopy (RAS) will be used to search for and stabilise highly ordered interfaces of reactive electrodes with electrolytes. The electrochemical interfaces of semiconductors prepared in this way then allow an in-depth analysis with respect to their (photo)electrochemical properties by complementary experimental methods such as impedance spectroscopy (EIS) or intensity-modulated photo spectroscopy (IMPS). In the case of battery electrodes, RAS will be used for instance to control the nucleation behaviour on anode materials or the formation of solid-electrolyte interphases (SEI), followed by the characterisation of ion transport over these interfaces by EIS. Modelling of the electronic structure of these systems by means of density functional theory will provide a further refined understanding of the interfaces and computational spectroscopy derived thereof will form the bridge to experiment. There hereby enabled control of highly ordered electrochemical interfaces will be used as a starting point to enable the synthesis of semiconductor hetero-structures in epitaxial quality with spectroscopic growth control. This can open up new paths for the design of photoelectrodes. Finally, room-temperature liquid-metal electrocatalysts will be synthesised and investigated with complementary spectroscopy as well as modelling to unravel their catalytic properties for the electrochemical reduction of CO2 to solid carbon. As the solid carbon initially nucleates as graphene(oxide) on the liquid-metal matrix, it will be evaluated, if the resulting interface can be used as a starting point for the growth of complex, ordered structures. The methods developed and insights gained in this project will therefore both improve the understanding of complex electrochemical interface, and create novel approaches for the spectroscopically-controlled, electrochemical synthesis of materials.