nitride (h-BN), [10] layered double hydroxides (LDHs), [11][12][13][14] graphitic carbon nitride (g-C 3 N 4 ), [15] transition metal dichalcogenides, [16][17][18] metal-organic frameworks (MOFs), [19,20] black phosphorene (BP), [21][22][23][24] MXenes, [25][26][27] and so on.With thicknesses of nanometers and lateral sizes ranging from tens of micrometers to less than a micrometer, the electron confinement in ultrathin 2D anisotropy endows these materials with compelling electronic characteristics and makes them promising candidates for fundamental condensed matter investigations and microelectronic applications. [28] Moreover, their single-atom thickness and large lateral size results in 2D nanosheets with extremely high specific surface areas and large numbers of active sites, which are favorable for surface-active applications such as electrocatalysis, [29][30][31][32][33][34][35][36] photocatalysis, [37][38][39][40] electrochemical energy storage, [41][42][43][44][45] and so on. In addition, 2D nanomaterials lend themselves to the fabrication of various flexible and transparent optoelectronic devices due to their high mechanical flexibility and optical transparency, ascribed to their extreme thinness and high Young's modulus. [46,47] More interestingly, using 2D materials as building blocks, it is possible to fabricate various van der Waals heterostructures with unprecedented properties that are absent from the individual components, including 2D/2D, 0D/2D, 1D/2D, and 3D/2D. [48][49][50][51][52][53][54][55] To realize these potential applications, attention has been focused on developing highefficiency, low-cost industrial-scale approaches for obtaining single or a few layers of ultrathin 2D nanomaterials. [56][57][58][59] To date, various synthetic strategies have been developed to fabricate 2D nanomaterials, such as mechanical cleavage, [2,60] liquid exfoliation, [61][62][63] and chemical synthesis. [64] All these methods can generally be classified into two types: bottomup and top-down approaches. The bottom-up strategies, such as epitaxial growth and chemical vapor deposition, are able to prepare large, ultrathin 2D materials; however, epitaxial growth and chemical vapor deposition are complicated and costly, requiring high temperatures and an additional transfer step from the substrate to the target surfaces. The need for multiple steps makes manufacturing difficult, and impurities or cavities can occur in the nanosheets. The top-down approach is more feasible for exfoliating bulk layered compounds, yielding highquality 2D nanosheets in large quantities. [61] Lately, electrochemical exfoliation methods are garnering enormous interest for their easy procedures, high controllability, 2D materials have captured much recent research interest in a broad range of areas, including electronics, biology, sensors, energy storage, and others. In particular, preparing 2D nanosheets with high quality and high yield is crucial for the important applications in energy storage and conversion. Compared with other prevail...