Gold nanobipyramid@cuprous oxide jujube-like nanostructures for plasmon-enhanced photocatalytic performance

Abstract

Nobel metal/semiconductor composites is a kind of alluring photocatalysts based on their broad light absorption and high photocatalytic efficiency. In this work, we reported a novel jujube-like gold nanobipyramid core/cuprous oxide shell (Au NBP@Cu2O) composite photocatalyst, with adjustable aspect ratio of Au NBP core and thickness of Cu2O shell. The Au NBP@Cu2O products possess tunable light absorption from visible to near-infrared region and all of them exhibit excellent photocatalytic performances compared with pure Cu2O. The optimal Au NBP@Cu2O sample achieves nearly 100% degradation of methyl orange in 60 min compared with 2.45% for pure Cu2O under illumination (λ > 400 nm), and 47.5% degradation of methyl orange in 60 min compared with 1.23% for pure Cu2O under illumination (λ > 700 nm). The enhanced photocatalytic behaviors are attributed to the efficient charge separation driven by Schottky junction in Au NBP@Cu2O, as well as the strong surface plasmon resonance effect from Au NBPs which not only extends the light response for Cu2O but also enhances the photodegradation by generating hot electrons to inject into Cu2O. Furthermore, it is worth mentioning that the Au NBP@Cu2O composites exhibit significantly enhanced stability because the Au NBP core can draw holes from Cu2O. This work may provide guidance to the fabrication of plasmon-enhanced photocatalysts based on Au NBPs and other semiconductors along with the exploration of wider applications for them in the future work.