Surface plasmon resonance effect enhances spin-polarized electrons to promote photocatalytic CO₂ reduction

The construction of chiral materials has always been a research hotspot in the field of inorganic chiral nanomaterials. By introducing chiral destructive agents, materials are endowed with chiral nanostructures, its unique chiral-induced spin selectivity (CISS) can be applied in the field of photocatalysis. Au nanoparticles (Au NPs) are a typical photosensitizer capable of producing surface plasmon resonance (SPR) effects, producing CO and CH₄ in photocatalytic CO₂ reduction. However, the activity of Au NPs is low, resulting in a low reaction yield. Therefore, we investigated the photocatalytic CO₂ reduction performance of the Au NPS deposited inorganic chiral bismuth bromide oxide nanomaterial photocatalyst (D-BiOBr/Au). It is worth noting that D-BiOBr/Au chiral materials enhance spin-polarized electrons due to SPR and CISS effect, and their photocatalytic CO₂ reduction performance is significantly better than D-BiOBr and original BiOBr without SPR and CISS effect. The CO yield of D-BiOBr/Au0.3 % is 24.39 μmol/g h^-1, which is 2.02 times of D-BiOBr and 2.43 times of BiOBr, respectively. In the Mc-AFM test, the tunnel current of D-BiOBr/Au0.3 % was the strongest, showing stronger spin-polarized electrons. The mechanism of photocatalytic CO₂ reduction was further studied by FDTD simulation. The reason for the improved photocatalytic CO₂ reduction efficiency of D-BiOBr/Au is the increase of spin-polarized electrons due to the SPR effect, thus prolonging the carrier lifetime and promoting spin-polarized electron-hole separation. The results show that enhancing spin-polarized electrons through SPR effect is an effective strategy to improve photocatalyzed CO₂ reduction in photocatalyzed semiconductors.