Zr-doped TiO2 for enhanced photocatalytic degradation of bisphenol A

Zr ions were successfully incorporated into the bulk lattice of TiO2 by a multi-step sol-gel process. The doping of Zr ions in TiO2 lattice reached about 30%. The Zr-doped TiO2 photocatalysts exhibited much higher photocatalytic efficiency than pure TiO2 in the degradation of bisphenol A (BPA) under UV irradiation and complete mineralization of BPA was achieved. The higher photocatalytic activity of Zr-doped TiO2 was attributed to gradually upward shift of the conduction bands with increasing Zr content, thus resulting in a stronger reduction power of photogenerated electrons and contributing to the improved photoactivity. The effects of initial BPA concentration, irradiation intensity. initial solution pH and inorganic anions on the photocatalytic performance of Zr-doped TiO2 were studied. The photoeegradation of BPA was found to be optimized under a basic condition at pH 9. The addition of PO43- and SO42- anions enhanced the photocatalytic reaction but NO3- and Cl- ions showed detrimental effects. (C) 2009 Elsevier B.V. All rights reserved.