Efficient water-mediated synthesis of bismuth oxyiodide with several distinct morphologies.

It is highly desirable to synthesize various micro/nanostructures of bismuth oxyhalides by facile methods and to further investigate these functional photoactive materials. Herein, we demonstrate a facile route to synthesize five distinct morphologies of BiOI microstructures via the solvothermal method. Notably, based on the morphology study of the intermediate products and the crystal structure analysis of the BiOI microstructures, the mechanism by which water modulates the crystal growth and finally mediates the morphology of BiOI microstructures was proposed. It is demonstrated that water can control the crystal growth, and increasing the amount of water can transform the growth from vertical to the (001) facets to parallel to them. By combining Ostwald ripening crystal reconstruction and self-assembly of nanostructures, the microstructures of BiOI can be precisely controlled. Therefore, the water-mediated strategy not only gives a new route for specific BiOI microstructure preparation but also provides new evidence for further understanding of the crystal growth mechanism of BiOI prepared by the wet-chemical method. [ABSTRACT FROM AUTHOR]