Facet-Dependent Catalytic Activity of Nanosheet-Assembled Bismuth Oxyiodide Microspheres in Degradation of Bisphenol A

\ Photocatalysts with,different exposed facets often exhibit different photochemical performances, but the underlying mechanisms are not fully understood. In this study, we synthesized two nanosheet-assembled bismuth oxyiodide (BiOI) microspheres with exposed (110) and (001). facets; respectively, to further investigate facet-dependent photo-catalytic activity. Our experimental results showed that the BiOI,microspheres with exposed (110) facets exhibited much greater catalytic activity than the BiOI ,microspheres with exposed (001) facets in the degradatron of bisphenol A under visible light irradiation. Density functional theory calculation revealed that the (HQ) facets can adsorb -a greater amount of O-2 and, thus, form more O-2. and OH, radicals than the (001) facets. The electron spin resonance spectrostopy and radical scavenging experiments verified that the BiOI microspheres with exposed (110) facets could produce a, greater amount of radicals than the BiOI microspheres with exposed (001) facets,: and more importantly, between the two BiOI products, only the BLOT microspheres with exposed (110) facets could,generate OH radicals directly. The facet-dependent radical formation mechanisms were previously unideritified. The findings Of this study may have important implications for the understanding of the facet-dependent photochemical performance of photocatalysts and the design of novel catalytic materials with inorganic nanostructures.