Heterophase Polymorph of TiO 2 (Anatase, Rutile, Brookite, TiO 2 (B)) for Efficient Photocatalyst: Fabrication and Activity.

TiO 2 exists naturally in three crystalline forms: Anatase, rutile, brookite, and TiO 2 (B). These polymorphs exhibit different properties and consequently different photocatalytic performances. This paper aims to clarify the differences between titanium dioxide polymorphs, and the differences in homophase, biphase, and triphase properties in various photocatalytic applications. However, homophase TiO 2 has various disadvantages such as high recombination rates and low adsorption capacity. Meanwhile, TiO 2 heterophase can effectively stimulate electron transfer from one phase to another causing superior photocatalytic performance. Various studies have reported the biphase of polymorph TiO 2 such as anatase/rutile, anatase/brookite, rutile/brookite, and anatase/TiO 2 (B). In addition, this paper also presents the triphase of the TiO 2 polymorph. This review is mainly focused on information regarding the heterophase of the TiO 2 polymorph, fabrication of heterophase synthesis, and its application as a photocatalyst.