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.