Fabrication of TiO2 Hollow Spheres Using Yeast as Bio-Templates and Their Photocatalytic Performance for the Degradation of CBW Wastewater

Hollow spheres of anatase TiO₂ have been prepared by using titanate butyl as titanium source and yeast as templates based on the surface bio-functionality of the microorganism, in which the yeast templates were calcinated to remove subsequently at 500°C. The products are characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and Fourier transform infrared spectrum (FT-IR). The results indicate that the formed TiO₂ hollow spheres have a regular spherical morphology with a diameter range from 2.5 to 2.8 μm. These spheres retained the morphology of the original yeast even though the yeast template was removed. Moreover, a possible formation mechanism involving a two-step encapsulation process is proposed. The photocatalytic performance of those hollow spheres for the degradation of CBW wastewater is investigated.