Phase Engineering and Synchrotron-Based Study on Two-Dimensional Energy Nanomaterials

In recent years, there has been significant interestin the developmentof two-dimensional (2D) nanomaterials with unique physicochemicalproperties for various energy applications. These properties are oftenderived from the phase structures established through a range of physicaland chemical design strategies. A concrete analysis of the phase structuresand real reaction mechanisms of 2D energy nanomaterials requires advancedcharacterization methods that offer valuable information as much aspossible. Here, we present a comprehensive review on the phase engineeringof typical 2D nanomaterials with the focus of synchrotron radiationcharacterizations. In particular, the intrinsic defects, atomic doping,intercalation, and heterogeneous interfaces on 2D nanomaterials areintroduced, together with their applications in energy-related fields.Among them, synchrotron-based multiple spectroscopic techniques areemphasized to reveal their intrinsic phases and structures. More importantly,various in situ methods are employed to provide deep insights intotheir structural evolutions under working conditions or reaction processesof 2D energy nanomaterials. Finally, conclusions and research perspectiveson the future outlook for the further development of 2D energy nanomaterialsand synchrotron radiation light sources and integrated techniquesare discussed.