Development of Earth-Abundant Transition-Metal Sulphide Catalysts for Photoelectrochemical Reactions beyond Water Splitting

• Applicant: Dr. Judith Zander
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 567179750

Solar energy conversion is at the heart of the transition towards a sustainable energy economy. Photoelectrochemical (PEC) conversion of abundant, low-value feedstock allows for the production of green fuels and important commodity chemicals, such as ammonia, by directly combining light absorption and catalysis into an integrated devices with sunlight as the only energy input. However, the efficiency and long-term stability of PEC systems still require significant improvement for large-scale industrial application - especially for challenging reactions such as ammonia production. In the proposed project these challenges are tackled by the design of novel photoelectrodes based on efficient PV-absorbers for the electrochemical reduction of nitrate, a major pollutant from agriculture and industry. The interface between absorber and catalyst will be engineered to achieve an efficient charge extraction to the electrocatalyst, as well as an efficient and selective production of ammonia at low overpotentials, in combination with long-term stability. Transition metal sulphides based on Ni, Fe, Co, and Mo will be optimised for the reduction of nitrate to ammonia on the cathode. To reduce the required overall potential and increase the product value, biomass oxidation will be employed on the anode side using similar sulphide catalysts. This strategy allows for valuable products to be made on both electrodes, doubling the value of the system. The combination of comparative measurements, detailed material characterisation and operando analysis shall culminate in the rational design of stable and efficient photoelectrodes, that allows solar ammonia production coupled to biomass valorisation to get one step closer to industrial implementation, and yields valuable insights for future development.

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Professor Thomas Francisco Jaramillo, Ph.D.