Facile and Fast Synthesis of Single-Crystalline Fractal Zinc Structures through a Solution Phase Reaction and Their Conversion to Zinc Oxide

We report a novel method for the synthesis of fractal Zn structures through a solution phase reaction. An Al-film-deposited substrate was immersed in an aqueous ammonia solution containing Zn ions and maintained at 95 degrees C for 5 min. After the reaction, the Al-deposited side of the substrate was found to be covered with fractal Zn structures. These Zn structures are highly oriented, and the Zn(002) planes are parallel to the substrate. They are single-crystalline and the average thickness of the plates is approximately 50 nm. On the basis of our results, we propose a mechanism for the spontaneous growth of such fractal Zn structures. Single-crystalline fractal ZnO structures can also be obtained by calcination of the as-synthesized fractal Zn crystals at 500 degrees C for 5 h in air. These fractal ZnO structures are highly oriented and inherit their morphologies from the Zn structures.