Solvothermal synthesis of flower-like BiOBr microspheres with highly visible-light photocatalytic performances
Hierarchical flower-like BiOBr microspheres assembled with nanosheets were synthesized via solvothermal method with both two-component solvent (ethylene glycol and isopropanol) and CTAB surfactant. The growth of BiOBr crystal was significantly influenced by the concentration of ethylene glycol and isopropanol in two-component solvent, the amount of CTAB surfactant and the solvothermal time. According to the photodegradation of rhodamine B (RhB) under visible-light irradiations, the high photocatalytic activity of hierarchical flower-like BiOBr microspheres could be ascribed to the enhanced visible-light absorbance via the light multi-reflections, the efficient separation of photo-generated electrons and holes, the high crystallization and the large surface area. The main active species during the photocatalytic reaction was determined as O2− radical by additionally dissolving the trapping agent in the solution. Meanwhile, BiOBr microspheres also exhibited the excellent durability owing to the stable crystal phase and microsphere morphology.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Hierarchical flower-like BiOBr microspheres assembled with nanosheets are prepared by solvothermal process in two-component solvent. ► The growth of BiOBr crystal is controlled by the ratio of ethylene glycol and isopropanol, the amount of CTAB surfactant and the solvothermal time. ► High visible photoactivity is due to strong light absorbance via light multi-reflections and efficient separation of photo-induced charges. ► The O2− radical is the main active species during the photocatalytic reaction. ► The durability of BiOBr photocatalyst is owing to the stable crystal phase and microsphere morphology.
Journal: Applied Catalysis B: Environmental - Volumes 111–112, 12 January 2012, Pages 334–341