Present Perspectives of Advanced Characterization Techniques in TiO2-Based Photocatalysts

TiO2 is the most investigated photocatalyst because of its nontoxicity, low cost, chemical stability, and strong photooxidative ability. Because of the morphology- and structure-dependent photocatalytic properties of TiO2, accurate characterization of the crystal and electronic structures of TiO2-based materials and their performance during the photocatalytic process is crucial not only for understanding the photocatalytic mechanism but also for providing experimental guidelines as well as a theoretical framework for the synthesis of high performance photocatalysts. In this review, we focused on the advanced characterization techniques that are utilized in the studies on the TiO2 structures and photocatalytic performance of TiO2 and TiO2-based materials. It is therefore anticipated that this review can provide a novel perspective to understand the fundamental aspects of photocatalysis and inspire the development of new photocatalysts with superior performances.