Bioinspired charge reservoir enables efficient CO2 photoreduction with H2O via tungsten valence oscillation

Solar-driven conversion of CO 2 and H 2 O into chemicals is a promising strategy, while achieving simultaneous and efficient CO 2 reduction and H 2 O oxidation remains challenging. Here, inspired by the role of plastoquinone in temporarily storing electrons during natural photosynthesis, we design a silver-modified tungsten trioxide (Ag/WO 3 ) that functions as a charge reservoir through reversible W 6+ /W 5+ transitions under irradiation. When coupled with various active components, Ag/WO 3 significantly enhances their CO 2 conversion performance, indicating the universality of this strategy. Specifically, coupling Ag/WO 3 with cobalt phthalocyanine (CoPc), the CoPc/Ag/WO 3 catalyst achieves a CO production rate of ~1.5 mmol g CoPc −1 h −1 , representing a 100-fold enhancement over pure CoPc. Mechanistic studies reveal that electrons stored in Ag/WO 3 efficiently scavenge photogenerated holes from CoPc, thereby maintaining a high electron density at CO 2 reduction sites of CoPc. This work establishes a bioinspired charge reservoir strategy for efficient CO 2 photoreduction, providing a universal approach to solar fuel production.