An overview of advanced methods for the characterization of oxygen vacancies in materials

Oxygen vacancy plays an important role in many fields, such as photocatalysis, energy storages, electrocatalysis, which has been widely investigated both by experiment and theoretical calculations. Herein, this review presents the new type and advanced methods to detect the existence of oxygen vacancies in nanomaterials, such as, electron paramagnetic resonance, synchrotron radiation-based X-ray absorption fine structure, X-ray photoelectron spectroscopy and positron annihilation spectroscopy measurements. In addition, we provide some perspectives on the challenge and new direction for future research in oxygen vacancy. We hope that this minireview can offer some useful contributions to the future development of defective nanomaterials for diverse application. (C) 2019 Elsevier B.V. All rights reserved.