TiO2-ZrO2 binary oxide catalysts were successfully prepared by a solid state reaction. The interaction between TiO2 and ZrO2 affected the photocatalytic efficiency of mixture. 50%TiO2-ZrO2 photocatalyst exhibited much higher photocatalytic activity than pure TiO2 and the standard Degussa TiO2 P-25 in the degradation of phenol under UV irradiation. The profound effect of binary oxide catalyst for phenol degradation is generally considered due to the high surface area, small particle size, anatase phase and high monoclinic phase of ZrO2 content, and the presence of more surface OH groups than that of the pure TiO2 and ZrO2 photocatalyst. A natural pH of 5 is favorable for the photodegradation of phenol by 50TiO(2)-ZrO2 solid state dispersion (SSD) and 90% TOC removal can be achieved in 90 min. Monoclinic form of ZrO2 is found to be more effective for photodegradation. The catalytic activity was affected by the preparation method. The observed photodegradation activity for phenol follows the order 50%TiO2-ZrO2 (solid state dispersion) >50%TiO2-ZrO2 (impregnation (IMP)) >50%TiO2-ZrO2 (sol-gel (SG)). (C) 2011 Elsevier B.V. All rights reserved.