Morphology evolution and excellent visible‐light photocatalytic activity of BiOBr hollow microspheres

Abstract

AbstractBACKGROUNDBiOBr is considered a competitive candidate TiO2‐alternative visible‐light‐driven photocatalyst owing to the unique layered structure and suitable band gap. In order to improve the inherent photocatalytic activity of BiOBr further, BiOBr hollow microspheres were prepared by a solvothermal system of Bi(NO3)3/CTAB/2‐methoxyethanol/PVP, and their visible‐light photocatalytic performance was evaluated by the degradation of colorless p‐nitrophenol (PNP) and bisphenol A (BPA).RESULTSBiOBr hollow microspheres exhibited superior visible‐light photocatalytic activity to their solid spherical or flowerlike counterparts in the decomposition of aqueous PNP and BPA as well as Degussa P25 TiO2. Superoxide radicals and photogenerated holes were confirmed to be responsible for the complete oxidization of the target pollutants. Additionally, BiOBr hollow microspheres can be reused five times without obvious activity loss.CONCLUSIONSFormation of BiOBr hollow microspheres followed oriented attachment and inside‐out Ostwald ripening growth as well as the synergetic effect between 2‐methoxyethanol and PVP, and the excellent photocatalytic activity of BiOBr hollow microspheres is due to the improved light‐harvesting efficiency, larger BET surface area, increased contact between the active species and target pollutants, shortened mass transfer and diffusion distance as well as fast interfacial charge carrier separation. © 2016 Society of Chemical Industry