Photo-enhanced enzyme-like activities of BiOBr/PtRu hybrid nanostructures.

The combination of semiconductor and metal nanocomponents represents an effective way for design of photocatalysts with high efficiency. It is expected that this strategy can be applied to design photo-regulated nanozymes. To prove this concept, BiOBr/PtRu hybrid nanostructures have been fabricated by depositing PtRu nanoparticles on BiOBr nanosheets through a templating co-reduction method. The formation of BiOBr/PtRu hybrid nanostructures was confirmed by TEM, XRD and XPS. BiOBr/PtRu hybrid nanostructures exhibited excellent enzyme-like activities (peroxidase, oxidase, ferroxidase) as well as the ability to scavenge DPPH free radicals. When exposed to light irradiation (λ > 420 nm), it was found that BiOBr/PtRu hybrid nanostructures not only exhibit improved photocatalytic degradation, but also exhibit enhanced peroxidase- and oxidase-like activity. Due to the photocatalytic effect and the higher charge separation and utilization efficiency caused by heterojunctions, a light-enhanced enzyme-like activity mechanism was proposed. These results will be of value to design high efficiency nanozymes using light for biological and environmental applications.