Construction of a multifunctional catalyst with bifunctional channel and inner electric field through surface grafting of β-Cyclodextrin

Enhancing photoinduced charge carrier separation is critical for photocatalysis. This study grafted the primary hydroxyl groups on the primary face of β-Cyclodextrin (β-CD) exhibiting low steric hindrance and high nucleophilicity on the surface of Silver phosphate (Ag 3 PO 4 ) to construct a composite photocatalyst, APCD, with bifunctional channel for electron transfer and pollutant delivery. Theoretical calculations and experimental characterizations revealed that the composite structure facilitates electron redistribution and induced an interfacial electric field. While the hydrophobic cavity of β-CD attracted interfacial electrons, promoting cyclic electron transport and enhancing charge carrier separation efficiency. Furthermore, the hydroxyl-rich outer surface of β-CD endowed APCD with high hydrophilicity, while its hydrophobic cavity selectively recognized organic pollutants via a host-guest interaction mechanism, accelerating pollutant enrichment. APCD-3 achieved 99.36 % degradation of Rhodamine B (RhB) within 40 min, exhibiting a reaction kinetics rate 11.86 times higher than that of pure Ag 3 PO 4 , along with excellent recyclability. Based on band structure and photocatalytic mechanism analyses, APCD-3 was confirmed to universally degrade dyes, antibiotics, and produce H 2 O 2 . In this study, a novel material with bifunctional channel for electron transfer and pollutant transport was ingeniously constructed via utilize the unique structure of β-CD, which provides a new approach for the development of composite photocatalysts with high carrier separation efficiency.