New insight into BiOX (X = Cl, Br, and I) hierarchical microspheres in photocatalysis

Abstract BiOX (X = Cl, Br and I) hierarchical microspheres were prepared using a solvothermal method. As a popular group of photocatalysts, adsorption capacity of BiOX with the special morphology was rarely reported. Its adsorption capacity was greatly improved with a specific surface area of as high as ∼23 mg/g. Also, from the crystal structure analysis, the exposed [1 0 2] facets are primary for BiOX microspheres ([0 0 1] facets for BiOX nanosheets), which is in favor of enhancing photocatalytic activity. In this work, we have also addressed the importance to consider the color change of BiOX when applied in photocatalysis, as oxygen/halogen vacancies may be generated. This work sheds a light on reconsidering the role of adsorption as well as the stability (reusability) of BiOX in photocatalysis is significant.