A self-assembled Methanosarcina barkeri-NH2-MIL-101(Fe) biohybrid enables efficient photocatalytic CO2-to-CH4 conversion.

Semi-artificial photosynthesis offers a promising route for converting CO2 into value-added chemicals. Herein, a novel self-assembled biohybrid of Methanosarcina barkeri and NH2-MIL-101(Fe) enables direct CO2-to-CH4 conversion, achieving a CH4 yield of 563.72 ± 23.75⋅μmol gcat-1 and nearly 100% selectivity. NH2-MIL-101 exhibits high CO2 adsorption without generating H2 as a by-product. The biohybrid showed enhanced light-harvesting, improved electron-hole separation, accelerated interfacial charge transfer, and increased abundance of membrane-bound redox-active mediators. Transcriptomic analysis revealed upregulation of key genes promoting methanogenesis via both hydrogenase- and cytochrome-dependent mechanisms. These findings demonstrate the potential of solar-powered, self-replicating biohybrid systems for efficient CO2-to-CH4 conversion.