3D Bi₂WO₆/TiO₂ hierarchical heterostructure: Controllable synthesis and enhanced visible photocatalytic degradation performances

A three-dimensional (3D) multicomponent oxide, Bi₂WO ₆/TiO₂ as an example, hierarchical heterostructure was successfully synthesized as a mat via a simple and practical electrospinning-assisted route. The asprepared hierarchical nanofibrous mat consisted of Bi₂WO₆ nanoplates growing aslant on the primary TiO₂ nanofibers. Interestingly, the nanoplates were further composed of nanoparticles with a size of less than 20 nm. Bi₂WO ₆ with different morphologies and microstructures could be obtained by adjusting the concentration of the precursor. From the mat (10 cm) to the nanoparticle (20 nm), this multicomponent oxide mat due to the self-supporting property could be layed or hung conveniently anywhere under solar irradiation and recycled easily. Due to the structure-property relationships, the 3D Bi ₂WO₆/TiO₂ hierarchical heterostructure exhibited enhanced visible photocatalytic activity over that of the bulk Bi ₂WO₆/TiO₂ powder (SSR), the Bi ₂WO₆ nanoparticles (BWO), and the TiO₂ sample in the decomposition of both acetaldehyde (CH₃CHO) in air and rhodamine B (RhB) in water which are typical model pollutants. Close investigation revealed that the surface area, grain size, and hierarchical heterostructure of the as-prepared Bi₂WO₆/TiO₂ mat could improve the photocatalytic activities.