Fig. 3
From: Ultrathin two-dimensional porous organic nanosheets with molecular rotors for chemical sensing
Morphology characterization of NUS-24 nanosheets. a Fluorescence photograph of NUS-24 bulk powder (scale bar, 3 mm. λ ex = 365 nm). Inset of a corresponding optical photograph (scale bar, 3 mm). b FE-SEM image of NUS-24 bulk powder (scale bar, 10 μm. scale bar of inset of b, 30 μm). c, d FE-SEM images of NUS-24 nanosheets deposited on AAO substrate (scale bar, 500 nm in c and 200 nm in d). The circulated rectangular areas indicate the 2D layered structure of NUS-24. e TEM image of NUS-24 nanosheets (scale bar, 200 nm). f HR-TEM image of NUS-24 nanosheets featuring the planar lattice structure (scale bar, 5 nm. Inset: the lattice distance). g The fast Fourier transformation of f (scale bar, 5 1 per nm). h The lattice structure from (660) plane of the optimized NUS-24 crystal structure. i–l AFM images of NUS-24 nanosheets dispersed in acetone (i, j), acetonitrile (k), or ethanol (l) (scale bar, 10 μm in i and 2 μm in j–l. Inset: the height of AFM image for selective area). m The statistical height distribution of NUS-24 nanosheets based on 322 AFM measurements. n The DLS results of NUS-24 nanosheets in different solutions. o The optical photograph of NUS-24 nanosheets in acetone solution indicating strong Tyndall effect. p The fluorescent photograph of NUS-24 nanosheets in acetone solution at 298 K (left, solution state) and 77 K (right, solidified state) (λ ex = 365 nm)
