Immobilization of BiOBr/BiOI Hierarchical Microspheres

Three-dimensional (3D) BiOBr/BiOI hierarchical microspheres were successfully fabricated on the surface of fly ash cenospheres (FACs) via a facile one-pot solvothermal method for the first time. The as-prepared samples were characterized by XRD, SEM, energy-dispersive X-ray spectroscopy, UV–visible diffuse reflectance spectroscopy, and high-resolution transmission electron microscopy. The results indicated that the loaded hierarchical microspheres exhibited a uniform distribution, and some aggregation was observed. These well-dispersed hierarchical microspheres were composed of 2D nanosheets, which possess heterojunction structures. Based on the photodegradation tests examining the removal of rhodamine B from water under visible light irradiation (l. 420 nm), the photocatalytic activity of BiOB/BiOI/FACs was superior to that of BiOBr/FACs and BiOI/FACs. A proposed mechanism for the enhanced photocatalytic activity displayed by BiOB/BiOI/FACs is discussed