Interfacing Broad-Spectrum Semiconductors with Hydrogenases for Semi-Artificial Solar Reforming of Cellulose

Semi-artificial photosynthesis offers a promising route for solar chemistry, but most biohybrid systems rely on UV or blue-light excitation, are limited by inefficient interfacial charge transfer or rely on sacrificial reagents. Here, we report a rationally designed hybrid system that integrates the broad-spectrum semiconductor BaTaO2N (up to ~680 nm) with carbon nitride (CNx) and the [FeFe]-hydrogenase (H2ase) from Clostridium pasteurianum for solar-driven biomass reforming. In this architecture, BaTaO2N serves as a robust broad-spectrum light absorber to complement the narrow UV-blue wavelength absorption of CNx, which functions as both a photoactive component and an interfacial conduit to shuttle photogenerated electrons transfer to [FeFe]-H2ase for H2 evolution. The optical advantage of the Ba-TaO2N|CNx|[FeFe]-H2ase hybrid enables markedly enhanced catalytic efficiency, achieving a H2 yield of 413 ± 21 μmol g−1 and a turnover number of 20,653 for cellulose reforming under simulated AM 1.5G irradiation at 25 °C. This work establishes a paradigm for semi-artificial photosynthesis by combining broad-band light harvesting, efficient charge transfer, and sustainable biomass valorization.