A novel yeast bio-template route to synthesize Cr2O3 hollow microspheres

Chromium oxide (Cr2O3) hollow microspheres were successfully prepared by using spherical yeast as a natural bio-template and chromium chloride hexahydrate (CrCl3·6H2O) as chromium source, which involved the deposition of inorganic coatings on the surface of yeast cells and subsequent thermal dehydration. Various approaches including X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transformed infrared (FT-IR) spectroscopy were used to characterize the intermediate and the final products. The results showed that the thermally treated samples were Cr2O3 hollow microspheres with a diameter varying between 2.5 μm and 2.8 μm. The possible mechanism for the formation of Cr2O3 hollow microspheres is proposed. This study provided a promising route for the preparation of a variety of hollow microspheres.