The amorphization strategies of two-dimensional transition metal oxide/(oxy)hydroxide nanomaterials for enhanced electrocatalytic water splitting

Amorphous two-dimensional transition metal oxide/(oxy)hydroxide (2D TMO/TMHO) nanomaterials (NMs) have the properties of both 2D and amorphous materials, displaying outstanding physicochemical qualities. Therefore, they demonstrate considerable promise for use in electrocatalytic water splitting applications. Here, the primary amorphization strategies for achieving the 2D TMO/TMHO NMs are comprehensively reviewed, including low-temperature reaction, rapid reaction, exchange/doping effect, ligand modulation, and interfacial energy confinement. By integrating these strategies with various physicochemical synthesis methods, it is feasible to control the amorphization of TMO/TMHO NMs while maintaining the distinctive benefits of their 2D structures. Furthermore, it delves into the structural advantages of amorphous 2D TMO/TMHO NMs in electrocatalytic water splitting, particularly emphasizing recent advancements in enhancing their electrocatalytic performance through interface engineering. The challenges and potential future directions for the precise synthesis and practical application of amorphous 2D TMO/TMHO NMs are also provided. This review aims to establish a theoretical foundation and offer experimental instructions for developing effective and enduring electrocatalysts for water splitting.