Fig. 3: The composition and structure of the W-ESO-B wood sample.

a FTIR spectra of the ESO-B film, WOOD sample, and W-ESO-B sample in the range of 3750-520 cm⁻¹. b–g Cross-sectional SEM images of the WOOD b, c and W-ESO-B d, e samples. EDS elemental mapping images for B (f) and N (g) of the W-ESO-B sample.