Facile synthesis of flower-like BiOI hierarchical spheres at room temperature with high visible-light photocatalytic activity

Highlights
- Flower-like BiOI hierarchical sphere is obtained in the presence of ethylene glycol.
- A template free hydrolysis route is employed at room temperature.
- Ethylene glycol plays an important role in assembling BiOI nanoflakes to form spheres.
- The BiOI sphere shows high visible-light photocatalytic activity and good stability.