Self-rising approach to synthesize porous hollow metal oxides

Porous hollow metal oxides are prepared using a novel self-rising approach. The method is 'hard-template' free and relatively easy to perform, utilizes inexpensive precursors and processing conditions, and is versatile, thus offering tremendous opportunities with a wide variety of conditions to explore to synthesize materials with hollow structures. Co3O4 and amorphous Sm(0.5)Sr(0.5)CoO3 as a model has been successfully synthesized, showing hollow structure with porous shell and possessing high BET surface areas. A tentative scheme is given to illustrate its synthetic mechanism.