Self-development of hollow TiO2 nanoparticles by chemical conversion coupled with Ostwald ripening

In this communication, the TiO2 materials with porous and hollow nanostructures were successfully synthesized through one-pot solvothermal process without any surfactant and template. Our study demonstrated that, the chemical conversion could induce the self-development of hollow TiO2 nanostructures coupled with the physical Oswald ripening process. In particular, the chemical conversion took place progressively from the particle surface to the core of an assembly, generating the converted TiO2 materials. The exterior TiO2 grains were quickly transformed to be a solid and stable surface shell of spheres. Continuous chemical conversion process for inner grains of spheres would lead to the formation of loose package of grains and thus could facilitate would the outward migration and deposition of inner grains onto the stable exterior shell of spheres. The depletion of interior material resulted in generation and development of hollow core structure. This study can be basis for the fabrication of hollow structures of different solid materials by one-pot solvothermal process. (C) 2015 Elsevier B.V. All rights reserved.