Internal electric field promoted charge separation via bismuth-based ternary heterojunctions with near-infrared light harvesting properties for efficient photoredox reactions

Abstract

1D-based heterostructured photocatalysts have attracted great attention in the field of solar-to-fuel conversion reactions owing to their distinctive electronic band structure and rich active sites. However, the rational design and interfacial charge carriers' regulation of 1D double S-scheme heterojunctions are still puzzling. In this work, a quaternary photocatalytic system of CdS/Bi/Bi₂WO₆/Bi₂S₃ (CBWO) with full spectrum utilization was developed. Photocatalytic tests revealed that the optimized CBWO heterostructured catalyst had the highest photocatalytic H₂ evolution rate under UV-vis-NIR light irradiation were 4.2 and 29 times that of pure CdS and BWO photocatalysts, respectively. Detailed experiments together with structural characterization and charge transfer properties reveal that the double S-scheme heterojunction and Schottky junction with metallic Bi could significantly promote electron enrichment, which offers highly efficient reaction networks to facilitate the conversion of 2H⁺ towards H₂ formation. These results provide a piece of important knowledge for the specific design and synthesis of excellent photocatalysts with full spectrum response in solar to H₂ conversion reactions.