Solvothermal synthesis of BiOI hierarchical spheres with homogeneous sizes and their high photocatalytic performance

► Bismuth oxyiodides were obtained by using PVP assisted solvothermal synthesis. ► Sphere-like hierarchical bismuth oxyiodides (BiOIs) have homogeneous size. ► Homogeneous BiOI spheres have high visible light photocatalytic activities.