Integrating plasmonic Au nanorods with dendritic like α-Bi 2 O 3 /Bi 2 O 2 CO 3 heterostructures for superior visible-light-driven photocatalysis

Abstract To explore the relationship between semiconductor structure and plasmonic noble metal nanoparticles (NPs) property is crucial for developing highly efficient visible light driven photocatalyst. Here, dendritic α-Bi 2 O 3 /Bi 2 O 2 CO 3 biphasic heterostructures were first synthesized by a facile and low-cost phase transformation method. Then, plasmonic Au NPs (including Au nanospheres (NSs, ∼30 nm)) and Au nanorods (NRs, ∼20, ∼30, and ∼35 nm) were loaded onto the α-Bi 2 O 3 /Bi 2 O 2 CO 3 heterostructure. The results revealed that these α-Bi 2 O 3 /Bi 2 O 2 CO 3 heterostructures exhibited much higher visible-light photocatalytic activities than α-Bi 2 O 3 for dye degradation. More importantly, compared to plain α-Bi 2 O 3 /Bi 2 O 2 CO 3 heterostructures, loading of Au NSs brought ∼4 times increase in activity and Au NRs 5–11 times depending on nanorods size. The significant boosting of activity is attributed to the large enhancement of charge separation by the formation of α-Bi 2 O 3 /Bi 2 O 2 CO 3 interface and more production of OH radicals by Au NSs or Au NRs. The surface plasmon resonance (SPR) absorption of these gold NPs on the α-Bi 2 O 3 /Bi 2 O 2 CO 3 heterostructures could also have significant contribution to the activities due to their strong plasmonic near-fields. This work demonstrates that tailoring the semiconductor substrate structure and the plasmonic noble metal NPs properties should constitute a promising strategy for the design efficient solar energy driven photocatalytic materials.