Figure 1.

Surface morphologies and characterization. a) Schematic diagram of the sulfonated PEEK coated with Ppy. b) Surface morphologies, elemental composition, and macroscopic photos of i) SP, ii) SPPL, iii) SPPM, and iv) SPPH. The inset on top right corner is high magnification of dash line marked area, respectively. c) Surface element content of each group. d) FTIR spectra. e) Raman spectroscopy. f) Simulation calculation of the bonding energies between pyrrole monomer and sulfonated PEEK substrate. i) Hydrogen bonds with ketone groups on the substrate; ii) Hydrogen bonds with sulfonic groups on the substrate; iii) Chemical cross‐linking with sulfonic groups.