Localized heating driven selective growth of metal-organic frameworks (MOFs) in wood: A novel synthetic strategy for significantly enhancing MOF loadings in wood

Highlights: • Localized heating driven selective growth of MOF crystals in the confined spaces. • Significantly enhanced MOF loadings in the wood scaffolds. • Highly efficient release of the adsorbed dye in MOFs triggered by localized induction heating. In-situ growing metal-organic frameworks (MOFs) in wood scaffold is greatly suppressed under the traditional solvothermal conditions, resulting in the production of MOF incorporated wood (MOF@wood) with extremely low MOF loadings so that their adsorption-associated applications are dramatically restricted. To overcome this challenge, localized magnetic induction heating (LMIH) selectively occurring on the lumen surface of wood is employed to drive in-situ MOF growth in wood. Surprisingly, the resulting MOF@wood exhibits over 50 times higher MOF loadings than the control sample synthesized with the conventional solvothermal reactions. Such a high MOF loading is mainly derived from the formation of an ideal solvothermal environment within the selectively heated wood scaffold, which makes energy-favorable MOF growth process prefers to take place inside of wood rather than its surrounding reaction medium. As a typical example, UiO-66-NH₂@wood with 49.6 wt% of MOF loading was synthesized. It not only exhibits excellent adsorption capacity towards methylene blue, but also can be highly efficiently regenerated with LMIH, highlighting the great potentials of our currently developed MOF@wood in adsorption-associated applications. Importantly, this work demonstrates that the localized heating of reaction system may provide a promising way to significantly promote in-situ growth of functional materials at selective locations.