The construction of type II heterojunction of Bi2WO6/BiOBr photocatalyst with improved photocatalytic performance

The Bi2WO6/BiOBr composites were synthesized via a simple one-step solvothermal method by using reactable ionic liquid of [C16mim]Br as Br source. XRD, XPS, SEM, and TEM were used to characterize the structure and morphology of the composites. Because of the IL, the Bi2WO6 nanoparticles uniformly covered on the surface of flower-like BiOBr, forming special flower-like Bi2WO6/BiOBr composites. The photoactivity of Bi2WO6/BiOBr was evaluted by the photocatalytic degradation of rhodamineB (RhB), methylene blue (MB), and colorless tetracycline hydrochloride (TC). The UV–vis DRS spectra indicated that the composites displayed enhanced visible light absorption. The photoelectrochemical and PL measurements confirmed the improved spatial transfer and separation of the charge carries and suppressed recombination of the charge carries. Because of enhanced light absorption and improved spatial transfer and separation of the charge carries, caused by construction of the Type II heterojuction and using [C16mim]Br as Br source, the composites showed dramatic photocatalytic activity. Based on the radical-trapping experiments, a possible photocatalytic mechanism has been proposed.