Semi-artificial photosynthesis interfaces biological catalysts with synthetic materials such as electrodes or light absorbers to overcome limitations in natural and artificial photosynthesis. The benefit of using biocatalysts in electrocatalytic CO2 reduction is their electrochemical reversibility that enables their operation at very low overpotentials with high selectivity. This presentation will summarise my research group’s progress in integrating the CO2 reducing enzyme formate dehydrogenase into bespoke hierarchical 3D electrode scaffolds and the exploitation in solar-powered catalysis. I will present the electrochemical features and characterisation of the biocatalyst-material interface and provide my team's understanding of the electrochemical properties of the immobilised formate dehydrogenase. This insight allows the wiring of the biocatalyst into electrocatalytic schemes, photoelectrochemical devices and photocatalytic systems for unique CO2 utilisation reactions. The fundamental insights gained by integrating isolated formate dehydrogenase in electrodes will be presented and the case be made that this enzyme allows opening a solar-to-chemical conversion space that is currently not accessible with purly synthetic or biological catalysts (see uploaded Image as example).Recent publications: (1) Lam et al., Angew. Chem. Int. Ed., 2023, in print. (2) Bhattacharjee et al., Nat. Synth., 2023, 2, 182-92. (3) Badiani et al., J. Am. Chem. Soc., 2022, 144, 14207-16. (4) Cobb et al., Nat. Chem., 2022, 14, 417-24. (5) Edwardes Moore et al., Proc. Natl. Acad. Sci. USA, 2022, 119, e2114097199. (6) Anton Garcia et al., Nat. Synth. 2022, 1, 77-86.Reviews: (1) Fang et al., Chem. Soc. Rev., 2020, 49, 4926–52. (2) Zhang & Reisner, Nature Rev. Chem., 2020, 4, 6–21. (3) Kornienko et al., Acc. Chem. Res., 2019, 52, 1439–44. (4) Kornienko et al., Nature Nanotech., 2018, 13, 890–99