fig2

Figure 2. (A) Water-vapor assisted visualization of monolayer graphene^[37]; Anisotropic liquefaction process of water droplets on the surface of (B) few-layer and (C) thick BP^[38]; (D) Schematic illustration of GLCs that has been useful in liquid-phase electron microscopy technique^[59]; (E) In situ TEM images of two different merging modes of adjacent nanobubbles observed in GLCs^[63]. Figures are adapted from references^{[37,38,59,63]} with permission. BP: Black phosphorus; GLCs: graphene liquid cells; TEM: transmission electron microscope.