Defective TiO2 with oxygen vacancies: synthesis, properties and photocatalytic applications

Abstract

Titanium dioxide (TiO₂), as an important semiconductor metal oxide, has been widely investigated in the field of photocatalysis. The properties of TiO₂, including its light absorption, charge transport and surface adsorption, are closely related to its defect disorder, which in turn plays a significant role in the photocatalytic performance of TiO₂. Among all the defects identified in TiO₂, oxygen vacancy is one of the most important and is supposed to be the prevalent defect in many metal oxides, which has been widely investigated both by theoretical calculations and experimental characterizations. Here, we give a short review on the existing strategies for the synthesis of defective TiO₂ with oxygen vacancies, and the defect related properties of TiO₂ including structural, electronic, optical, dissociative adsorption and reductive properties, which are intimately related to the photocatalytic performance of TiO₂. In particular, photocatalytic applications with regard to defective TiO₂ are outlined. In addition, we offer some perspectives on the challenge and new direction for future research in this field. We hope that this tutorial minireview would provide some useful contribution to the future design and fabrication of defective semiconductor-based nanomaterials for diverse photocatalytic applications.