Figure 1.

Nano–micro–macro trans-scale crafting and morphology-retaining pyrolysis of cellulose nanofiber paper (CNP). Schematics of (a) the nano–micro–macrostructural design and morphology-retaining pyrolysis of CNP and (b) the pretreatment and pyrolysis of CNP at different temperatures. Optical and field-emission scanning electron microscopy (FE-SEM) images of pyrolyzed CNP (c) without and (d) with I₂ treatment. FE-SEM images of pyrolyzed CNP prepared using (e and f) spatially controlled drying and (g–i) microembossing. Optical images of the (j) origami- and (k) kirigami-processed CNPs before and after pyrolysis. White and black papers indicate the original and pyrolyzed CNPs, respectively. Scale bar in (j and k): 10 mm. Pyrolysis temperature: 600 °C (e–k) or 1100 °C (c and d).