During the synthesis of the COF@bio composite, the addition of CNT significantly influenced the morphology of the composites, leading to the in situ growth of COF@bio on the exterior walls of the CNTs. Consequently, COF@bio-20 and COF@bio-40 exhibited relatively regular microspheres with tubular structures and numerous large aggregates (Figs. and). SEM images clearly show that COF@bio was uniformly wrapped around the outer surface of the CNT in the nanocomposite, further confirming the successful preparation of the composites. Additionally, the COF@bio composites displayed a smooth CNT morphology with no additional materials wrapped around them. These results strongly suggested that the in situ growth method yielded consistent morphology. Comparing the SEM images of COF@bio-20 and COF@bio-40, the latter displayed a smaller pipe diameter, indicating less wrapping around the outer surface of the CNT and resulting in a larger specific surface area. The TEM images of COF@bio (Fig. ) also demonstrated that COF@bio exhibited a spherical morphology. Furthermore, energy dispersive spectroscopy (EDS) mapping images of COF@bio revealed that the C, N, and O elements were homogeneously distributed (Fig. ), confirming the successful preparation of pure COF. Selected area electron diffraction (SAED) of pure COF@bio was consistent with the XRD data, illustrating fine crystallinity (Fig. ). Additionally, TEM analysis was conducted to examine the morphology of COF@bio-20, COF@bio-40, and CNT (Figs. and). The two composite materials exhibited tubular morphology, with C, N, and O elements evenly dispersed, which reflected one aspect of the successful preparation of the CNT composites.