Synergistic coupling of interface ohmic contact and LSPR effects over Au/Bi 24 O 31 Br 10 nanosheets for visible-light-driven photocatalytic CO 2 reduction to CO.

The challenge of synergistically optimizing different mechanisms limits the further improvement of plasmon-mediated photocatalytic activities. In this work, an Au/Bi 24 O 31 Br 10 composite, combining an interface ohmic contact and localized surface plasmon resonance (LSPR), is prepared by a thermal reduction method. The LSPR effect induces the local resonance energy transfer effect and the local electric field enhancement effect, while the interface ohmic contact forms a stronger interface electric field. The novel synergistic interaction between the interface ohmic contact and LSPR drives effective charge separation and provides more active sites for the adsorption and activation of CO 2 with improved photocatalytic efficiency. The optimized 0.6 wt% Au (5.7 nm) over Bi 24 O 31 Br 10 nanosheets showed an apparently improved photocatalytic activity without any sacrificial reagents, specifically CO and O 2 yields of 44.92 and 17.83 μmol g -1 h -1 , and demonstrated superior stability (only lost 6%) after continuous reaction for 48 h, nearly 5-fold enhanced compared to Bi 24 O 31 Br 10 and a great advantage compared with other bismuth-based photocatalysts.