Fig. 4

[A] FTIR spectra for Titanium dioxide nanowires (TNWs), Biochar nanorods (BC), In-situ modified titanium dioxide nanowires (ITB), and ex-situ modified titanium dioxide nanowires (ETB). [B-C] Zooming in FTIR peaks showing more details in the ranges from ~ 1450 to ~ 1800 cm^− 1 and from ~ 410 to 520 cm^− 1.