Room temperature, template-free synthesis of BiOI hierarchical structures: visible-light photocatalytic and electrochemical hydrogen storage properties.

Three-dimensional (3D) flower-like BiOI hierarchical structures have been successfully synthesized by a solution route at room temperature. The obtained sample was systematically studied by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). It is noteworthy that no surfactant or assisted reagent was needed during the formation of this uniform flower-like structure. It was proposed that primary nanoflakes of Bi-EtOH complexes were initially formed in the solution, and then anisotropic growth led to the development of 3D flowerlike structures. In addition, the photocatalytic property of the sample under visible-light was investigated with three types of dye: heteropolyaromatic (Methylene Blue (MB)), azoic (Methyl Orange (MO)) and phenol (rhodamine B (RhB)). High photocatalytic activity was observed for the phenol dye RhB. The electrochemical hydrogen storage properties were also investigated.