Subnano Polyhydroxylated\nC<sub>60</sub> and Co-oxo\nClusters Enable Accelerated Electron Kinetics for CO<sub>2</sub> Photoreduction\nin Pure Water

Accelerating the electron kinetics\nis critical for enhancing the\nphotocatalytic performance of CO<sub>2</sub> conversion. Herein, polyhydroxylated\nC<sub>60</sub> (C<sub>60</sub>OH, ∼1.8 nm) was molecularly\ndecorated on boron-doped carbon nitride (BCN) nanosheets via a hydrogen-bonding\nassembly process. Subsequently, subnano Co-oxo clusters (∼0.4\nnm) were precisely deposited on the BCN counterpart using a photohole-induced\napproach. The optimized nanocomposite photocatalyst, featuring spatially\nseparated dual subnano modifiers, exhibits a 10-fold CO<sub>2</sub> conversion rate of that for BCN in pure water and nearly 100% selectivity\ntoward CO by completely inhibiting H<sub>2</sub> evolution. Notably,\nthe apparent quantum yield reaches 3.51% (405 nm), surpassing that\nof representative cocatalyst-involved (boron-doped) carbon nitride-based\nphotocatalysts under similar conditions. Femtosecond-transient absorption\nspectra reveal that C<sub>60</sub>OH and Co-oxo clusters can rapidly\nextract electrons and holes, respectively, with balanced transfer\nrates. Moreover, the hydroxyl groups of C<sub>60</sub>OH can serve\nas CO<sub>2</sub> adsorption and catalytic sites, whereas Co-oxo clusters\nare capable of catalyzing water oxidation. The synergy between dual\nsubnano modifiers effectively improves the electron kinetics, resulting\nin an electron transfer efficiency of 41.1% determined by in situ\nmicrosecond-transient absorption spectroscopy. This work provides\na rational design strategy for developing advanced photocatalysts\nby modulating electron kinetics.