(a) surfactant (white spheres, hydrogen; gray spheres, carbon; red spheres, nitrogen) used in the synthesis of a hierarchical material with zeolite walls (b) SEM, and (c, d) TEM images of the resulting material. Insets in (c) and (d) Fourier diffractograms, for structural comparison, an MFI framework model is given in the bottom right inset of (d). Adapted from [259].
