Self-Assembled Protein Hybrid Nanofibrils for Photosynthetic Hydrogen Evolution

In artificial photosynthesis systems,synthetic diiron complexes are popular[FeFe]-hydrogenase mimics,which are attractive for the fabrication of photocatalyst-protein hybrid structures to amplify hydrogen(H2)generation capability.However,constructing a highly bionic and efficient catalytic hybrid system is a major challenge.Notably,we designed an ideal hybrid nanofibrils system that incorporates the crucial components:(1)a[FeFe]-H2ase mimic,which has a three-arm architecture(named triFeFe)for more interaction sites and higher catalytic activity and(2)uniform hybrid nanofibrils as the biological environment in which cysteine-catalyst coordination and the hydrogen-bonding network play a vital role in both catalyst binding and hydrogen evolution reaction activity.The assembled hybrid nanofibrils achieve efficient H2 generation with a turnover number of 2.3×103,outperforming previously reported diiron catalyst-protein hybrid systems.Additionally,the hybrid nanofibrils work with photosynthetic thylakoids to produce H2,without extra photosensitizers or electron shuttle proteins,which advances the bioengineering of living systems for solar-driven biofuel production.