Wood modification for the synthesis of MOF@wood composite materials with increased metal-organic framework (MOF) loading

Abstract

For potential applications it is necessary to shape metal-organic frameworks (MOFs) into composite materials. Due to its naturally porous and highly ordered structure, wood is a candidate for the synthesis of MOF-composite materials. Herein, we report two easy wood functionalization methods using maleic anhydride (MA) and (3-aminopropyl)triethoxysilane (APTES) to achieve MOF@wood composites with increased, in situ formed MOF loading compared to unfunctionalized wood. With the carboxylate-donating maleate anchor from MA and the carboxylate MOF MIL-53(Al) or with the amino-donating anchor APTES and the imidazolate MOF ZIF-8 MOF loadings up to 13 wt% could be reached in each case, forming composites with micro-meso-macrohierarchical porosity. The resulting composite materials were tested for water purification, represented by the adsorption of methylene blue, and heterogeneous catalysis, represented by the Knoevenagel condensation between benzaldehyde and malononitrile. Both potential applications were tested under static and continuous conditions, showing promising results for the application of MOF@wood composite materials in flow-through filtration and catalysis.