Reduction of structural hierarchy translates into variable influence on the performance of boron nitride aerogel

The rise of ceramic aerogel offers traditional ceramics a new window. Alongside the emerging prospects, what is open to explore includes the elegant design of a ceramic aerogel with tailorable inner organizations, what would occur when complex hierarchy exists in such an already intricate system, and how the properties get influenced as the complexity fades. Borrowing the wisdom from supramolecular world, we exquisitely transform BN aerogel from a complex hierarchy to a flatten microstructure based on solvent-induced morphology switch of its supramolecular precursor gel. Such reduction in structural hierarchy has insignificant effect on the thermal conductivity (∼0.027 W/(m·K)) but shifts the wettability from hydrophobicity to hydrophilicity and occasions nearly 3-fold difference in ion adsorption rate, as exemplified by lead ions. This work may promote the understanding of special hierarchy existing in delicate systems and inspire other attempts to harness the functionality of aerogels by manipulating structural hierarchy.