Hydrothermal synthesis of TiO 2 –yeast hybrid microspheres with controllable structures and their application for the photocatalytic reduction of Cr ( VI )

BACKGROUND Nanoparticle TiO 2 and biological yeast cells have been investigated in previous work. However, the formation of TiO 2 –yeast hybrid materials with controllable structures is rarely reported. In the present study, the hydrolysis of titanium tetrabutoxide ( TBOB ) on the surface of yeast cells was proposed to prepare controllable structures of TiO 2 –yeast hybrid microspheres. It also develops and widens the applications of TiO 2 –yeast hybrid microspheres for removal of Cr( VI ). RESULTS FE‐SEM and EDS revealed that the TiO 2 –yeast hybrid microspheres have rough surface morphology and uniform diameter. The XRD pattern indicated anatase phase TiO 2 nanoparticles with amorphous yeast. FT‐IR spectroscopy demonstrated that the formation of controllable TiO 2 –yeast composite microspheres was related to surface chemical functional groups of yeast. The composite microspheres possessed enhanced light response over the wide range 250–435 nm. The photocatalytic performance of TiO 2 –yeast (1.3 mL TBOB ) composite microspheres exhibited a maximum removal rate of 99% for the reduction of Cr( VI ) under UV light irradiation. CONCLUSIONS TiO 2 –yeast hybrid microspheres with controllable structures were successfully synthesized via a hydrothermal method. The diameter of TiO 2 –yeast microspheres decreased with increase of the amount of TBOB . No significant decrease in photo‐activity was found when used for the reduction of Cr( VI ) and the composites could be re‐used repeatedly without other treatment. © 2014 Society of Chemical Industry