Controllable fabrication of Fluorite-type Bi4MoO9 nanocrystals with well-defined octahedral shape for visible-light photocatalytic degradation

The Fluorite-type Bi4MoO9 nanocrystals with well-defined octahedral shape were successfully synthesized via a facile hydrothermal route. The structural transformation from the Aurivillius-type Bi2MoO6 nanocrystals to the Fluorite-related nanocrystals (Bi4MoO9) can be efficiently and precisely controlled by regulating the pH value of the reaction. The influences of reaction time and temperature were investigated to gain a deep understanding of the formation process of octahedral-shaped Bi4MoO9. Furthermore, the photocatalytic activity results showed that the octahedral Bi4MoO9 single crystals manifested excellent photocatalytic activities for the degradation of tetracycline (TC), rhodamine B (RhB), and bisphenol A (BPA). Additionally, the possible degradation intermediates of TC were unraveled and the ecotoxicity changes of identified TC intermediates were evaluated in detail. This present study develops a novel morphology structure of Bi4MoO9 and highlights its promise in the field of environmental remediation. [Display omitted] •Bi4MoO9 nanocrystals with a well-defined octahedral structure was synthesized.•The structural transform from Aurivillius-type to Fluorite-type was realized.•Fluorite-type Bi4MoO9 exhibited superior photocatalytic activity.•The degradation mechanism and ecotoxicity of TC was discussed.