Construction of flower sphere Bi4O5Br2/Bi2WO6 heterojunction for highly selective CO evolution in photocatalytic CO2 reduction without sacrificial reagents

Given the increasing interest in converting CO 2 into clean energy through photocatalytic processes, a Bi 4 O 5 Br 2 /Bi 2 WO 6 heterojunction photocatalyst was successfully constructed via a hydrothermal process combined with an in situ growth technique for efficient CO 2 photoreduction. Without sacrificial agents, the composite material 20Bi 4 O 5 Br 2 /Bi 2 WO 6 (20BOB/BWO) demonstrated superior photocatalytic activity. The generation rates of CO and CH 4 reached 25 µmol·g −1 ·h −1 and 4.6 µmol·g −1 ·h −1 , respectively; notably, the CO yield was significantly higher than that of pure Bi 4 O 5 Br 2 and Bi 2 WO 6 . Such enhancement originated from the type-II interfacial charge transfer mechanism, which facilitated efficient spatial charge separation and consequently led to a remarkable improvement in the composite’s catalytic efficiency.