Figure 4: Morphology study of MOF thin films prepared using different reaction times.

SEM images of MOF thin films prepared at (a) 420 s; (b) 300 s; (c) 180 s; and (d) 60 s. Images (e–h) show the cross-section views of the specimens in images (a–d) respectively. Scale bar, 1μm (a–h).