Metal Bi-coupled chiral nanoscale structures enhance spin-polarized electrons to promote photocatalytic CO2 reduction

The circular dichroism (CD) signal of D-BiOBr/Bi 0.3 g flipped and intensified. • The nanosheets of D-BiOBr/Bi 0.3 g were arranged in a spiral (counterclockwise) manner, forming petal-shaped nanospheres. • 0.3 g D-BiOBr/Bi exhibits a CO production rate of 84.27 μmol・g −1 h −1 , 3.34 times the value of D-BiOBr and 4.00 times that of 0.3 g pristine BiOBr/Bi sample. • LSPR boosts the migration of spin−down polarized electrons and improves the separation efficiency of photogenerated electron−hole pairs. Chiral inorganic nanomaterials have shown considerable promise in photocatalysis, owing to their distinctive optical activity and asymmetric interfacial effects. Metallic bismuth (Bi) exhibits a localized surface plasmon resonance (LSPR) effect, which markedly enhances both the generation and separation efficiencies of photogenerated electron-hole pairs. By employing D-sorbitol as a chiral inducer, we successfully synthesized chiral D-BiOBr/Bi nanocomposites. We propose that the synergistic integration of metallic Bi and chiral BiOBr enables effective modulation of chirality-induced spin selectivity (CISS), thereby enhancing spin polarization and promoting CO production from CO 2 reduction. Among the prepared samples, D-BiOBr/Bi 0.3 g exhibited the highest photocatalytic CO 2 reduction activity, selectively converting CO 2 to CO. The CO production rate of D-BiOBr/Bi 0.3 g was 84.27 μmol g −1  h −1 , which was 4.00 times and 3.34 times that of BiOBr/Bi 0.3 g and D-BiOBr respectively. Furthermore, magnetic conductive atomic force microscopy (Mc-AFM) measurements revealed that D-BiOBr/Bi 0.3 g generated the strongest tunneling current with an opposite polarity compared to its controls, providing indirect evidence for CISS-associated spin-selective charge transport. Collectively, our findings demonstrate a strong coupling between the LSPR of metallic Bi and structural chirality, which cooperatively boosts spin-polarized electron generation, accelerates electron-hole pair separation, and significantly improves photocatalytic CO 2 reduction performance.