General Water-Induced Self-Exfoliation Strategy for the Ultrafast and Large-Scale Synthesis of Metal Hydroxide Nanosheets

Metal hydroxides nanosheets of atomic thickness have attracted much interest due to their great potentials in catalysis, energy storage devices, and so on. However, the lack of efficient synthesis of 2D nanosheets has critically impeded their practical applications. Herein, we develop a general water-induced self-exfoliation (WISE) strategy to achieve the fast synthesis of metal hydroxide ultrathin nanosheets with almost single-layer atom thickness in a large scale. In a typical process of layered cobalt hydroxide (LCH) nanosheets, the presynthesized cobalt acetate hydroxide precursor is directly exfoliated to form nanosheets under the attack of H₂O in a few seconds. The water-induced self-exfoliation mechanism has also been proposed based on the analysis of the designed alcohol-mediated slow-down process. In addition, the used solutions and effluents can be recycled making WISE a green, efficient, and surfactant-free method. Furthermore, this general strategy can also be applied to synthesize other layered metal hydroxide nanosheets.