This review summarizes the preparation methods of mixed-phase TiO₂ photocatalysts. Two main lines of fabrication have been followed: one is preparation of mixed-phase TiO₂ in situ (e. g. hydrothermal method, solvothermal method, sol-gel method and microemulsion-mediated hydrothermal method, etc.), and the other is physical mixing of different phases of TiO₂ or calcinations under high temperature (e. g. solvent mixing and calcination treatment, calcination under high temperature, etc.). The latter has fewer requirements on the equipments, but the produced TiO₂ nanoparticles tend to be aggregates, which affects the photocatalytic performance of TiO₂ materials seriously. The former has more advantages in practical applications. At the same time, this review summarizes and remarks the researches on photocatalytic mechanisms of the mixed-phase TiO₂. Furthermore, the applications of the mixed-phase TiO₂ photocatalysts in environmental and energy fields are also prospected.

Contents
1 Introduction
2 Synthesis of the mixed-phase TiO₂ photocatalysts
2.1 Phases of TiO₂
2.2 Methods of preparing the mixed-phase TiO₂ photocatalysts and their influencing factors
3 Mechanisms of the enhanced photocatalytic activities by the mixed-phase TiO₂ photocatalysts
4 Conclusion and outlook