Effect of Alloyed BiOClxBr1‐x Nanosheets Thickness on the Photocatalytic Performance.

Promoting the separation of electrons and holes for photocatalysis is still challenging. In this paper, alloyed BiOClxBr1‐x nanosheets are synthesized to enhance the separation of electrons and holes by means of adjusting the thickness and the exposing specific crystal facet of nanosheet. SEM shows that the average thicknesses of samples are in the range of 34.7 to 47.2 nm. TEM analysis demonstrates that alloyed nanosheets obtained by codeposition method at room temperature have an exposure of (001) facet. Compared with pure BiOCl or BiOBr nanosheets, BiOClxBr1‐x nanosheets exhibit a greatly enhanced photocatalytic activity for degrading RhB. In addition, BiOCl0.5Br0.5 (BC5) sample with nanosheet thickness of 34.7 nm displays the highest photocatalytic activity, which is 17‐time higher than that of pure BiOCl or BiOBr nanosheets. The superior photoactivity of BiOClxBr1‐x nanosheets is attributed to the diverse light absorption, alloyed effect and different diffusion distance along [001] orientation. This study presents a 2D photocatalyst for degrading toxic pollutants to remedy environmental pollution. The revealing about the effect of thickness on photocatalytic properties could provide a new method to study the photoelectric properties related to 2D nanomaterials. The thickness of alloyed BiOClxBr1‐x nanosheets with an exposure of (001) facets affects the transfer and separation of electrons and holes in photocatalyst under the built‐in electric field (IEF) with the visible light irradiation, boosting the photocatalytic degradation of RhB. Holes diffuses onto the surface of BiOClxBr1‐x nanosheets and oxidize RhB to CO2 and H2O, remedying the relative environmental pollution problem. [ABSTRACT FROM AUTHOR]