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

TLDR

Titanium dioxide is a widely studied semiconductor whose photocatalytic performance is governed by defect disorder, particularly oxygen vacancies that affect light absorption, charge transport, and surface adsorption. This review surveys synthesis strategies for oxygen‑vacancy‑rich TiO₂, evaluates how these defects alter structural, electronic, optical, and adsorption properties, and outlines future challenges for designing defective semiconductor nanomaterials for photocatalysis. The authors analyze synthesis methods for inducing oxygen vacancies, characterize the resulting defect‑related structural, electronic, optical, and adsorption properties, and describe their influence on 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.