Natural AIEgens\nas Ultraviolet Sunscreens\nand Photosynergists for Solar Fuel Production

Bio-nano hybrids (BNH), combining semiconductors and\nmicroorganisms,\nhave shown great promise for effective solar-to-fuel energy conversion.\nHowever, the high-energy ultraviolet (UV) photons in the solar spectrum\ncan cause severe photocorrosion of semiconductors and irreversible\nphotodamage to microorganisms within BNH. Here, we developed an encapsulation\nstrategy using natural luminogens with aggregation-induced emission\ncharacteristics (AIEgens) to construct a protective layer for BNH,\neffectively shielding them against high-energy UV photons. We incorporated\nnatural berberine (BBR) into the BNH composed of Methanosarcina\nbarkeri and polymeric carbon nitrides (CN<sub><i>x</i></sub>). The self-assembled BNH–BBR system displayed\na 2.75-fold higher CH<sub>4</sub> yield than BNH under simulated solar\nirradiation. Mechanism analysis revealed that BBR acted as a UV sunscreen\nfor BNH by converting high-energy short wavelengths into low-energy\nlong wavelengths, thereby reducing the accumulation of reactive oxygen\nspecies and alleviating the photocorrosion of CN<sub><i>x</i></sub>. Furthermore, BBR functioned as a photosynergist for BNH by\nregulating photoelectron production and utilization, enhancing the\nintracellular energy formation in M. barkeri for growth and metabolism. This work provides important insights\ninto the effective and scalable conversion of CO<sub>2</sub> into\nvaluable biofuels with BNH under light illumination containing high-energy\nphotons.