In situ growth of COFs within wood microchannels for wastewater treatment and oil-water separation

• The Wood/COF was prepared via a simple in-situ growth strategy. • The Wood/COF shows high removal efficiency for iodine, dye and oil in wastewater. • The block sample has excellent recyclability and durability. • The preparation process of in-situ growth is low-cost, simple and environmental-friendly. • This is the first example of combining COFs with wood. The applied performance of covalent organic frameworks (COFs) is usually limited by their powder form and poor recyclability. In this work, natural balsa wood was employed as substrate for anchoring COFs nanoparticles. By in situ growth strategy, COFs was uniformly deposited on the microchannels of wood to construct Wood/COF composite with unique porous structure. The COFs grafted on the microchannels and porous structure of wood show excellent adsorption capacity in wastewater and oil-water separation. Moreover, the composite exhibited exceptional recyclability, stability and solvent resistance performance. Such wood-based composite is environmentally friendly and low cost, and we believe it has broad applications for practical wastewater treatment.