Controlled Hydrothermal Synthesis of Nickel Phosphite Nanocrystals with Hierarchical Superstructures

The large-scale synthesis of the hexagonal Ni 11 (HPO 3 ) 8 (OH) 6 nanocrystallites with delicate morphologies, such as nanoparticles, ellipsoidal rods, dumbbell-like and urchinlike superstructures based on nanorods as well as hollow spheres made of nanoparticles, have been prepared via a very simple hydrothermal method without any templates or catalyst. It is found that the morphology of the final products is strongly dependent on the reaction conditions, such as pH, temperature, and reaction times. A “rod-to-dumbbell-to-sphere” growth mechanism has been proposed for the formation of the urchinlike superstructures.