Flower-like BiOCl/BiOBr microsphere coated with Bi2WO6 nanoflakes as Z-scheme photocatalyst for dye degradation

Hydrangea-like BiOCl/BiOBr@Bi 2 WO 6 (CBW) core/shell microspheres are successfully synthesized, in which the BiOCl/BiOBr microspheres are coated with upright and thin Bi 2 WO 6 nanoflakes . The hierarchical composite photocatalysts generate abundant heterojunctions , meanwhile, it possesses large specific surface area and displays much enhanced adsorption-enrichment ability towards dyes. Thus, CBW photocatalysts exhibit improved removal ability towards Rhodamine B (RhB) due to the synergistic effect of adsorption and photocatalytic degradation. Under the visible light irradiation, CBW-3 synthesized at a W:Cl:Br ratio of 1:3:1 could remove 91.3 % RhB in 90 min with a significantly accelerated speed. CBW also displays good reusability, and it can be used to continuously remove dyes from wastewater. This study may arouse in-depth investigations on the design and synthesis of visible light photocatalytic materials. • BiOCl/BiOBr@Bi 2 WO 6 (CBW) microspheres are prepared by a solvothermal process. • CBW consists of inner BiOCl/BiOBr microsphere and outer Bi 2 WO 6 nanoflakes. • CBW possesses multiple heterojunctions and hierarchical nanostructure. • CBW obtains enhance visible light absorption and utilization. • CBW photocatalysts exhibit excellent dye degradation performance.