Hydrothermal synthesis of ZnO hollow spheres using spherobacterium as biotemplates

By using spherobacterium Streptococcus thermophilus as a natural biotemplate, ZnO hollow spheres have been synthesized in a simple hydrothermal method based on the surface biofunctionality of the microorganism, followed by calcination. The as-obtained products are characterized by techniques of XRD, FESEM, TEM and N-2 adsorption. Furthermore, a possible formation mechanism involving a two-step encapsulation process is proposed which has an effect on the bimodal pore structure of the products with pores in the mesoporous range. The research introduces a new concept to synthesize porous hollow spheres by using spherobacterium as a biological template and opens up a new pathway to synthesize hollow nanospheres, nanotubes and other kinds of 3D nanostructures with bacterium as the template via simple chemical routes. (c) 2006 Elsevier Inc. All rights reserved.