A simple and sequential strategy for the introduction of complexity and hierarchy in hydrogen-bonded organic (HOFs) crystals for environmental applications

Abstract

Hydrogen-bonded organic frameworks (HOFs) are a new class of crystalline porous organic molecular materials (POMMs) with great potential for a diverse range of applications. HOFs face common challenges to POMMs, and in general to purely organic crystals, that is, the difficulty of integrating multiple hierarchies in crystals. Herein, we proposed a simple and sequential strategy for the formation of hierarchical HOFs, including combined hierarchies in composition, architecture, and porosity. The strategy is based on controlling the assembly conditions, avoiding the use of any surface functionalization or template and obtaining hierarchical crystalline porous structures in an easy manner. As proof of concept, we demonstrate that hierarchical HOF crystals can be used to assemble crystals with superhydrophobicity and trapping abilities for the capture of persistent water contaminants such as oils and microplastics. We expect that this strategy could serve as inspiration for the construction of more intricated multiscale structures that could greatly expand the library of HOFs materials.