fig3

Figure 3. XPS characterization of CoFe₂O₄ and PANI@CoFe₂O₄. (A-D) Survey, Co 2p, Fe 2p, and O 1s spectra of CoFe₂O₄; (E-I) Survey, N 1s, Co 2p, Fe 2p, and O 1s spectra of PANI@CoFe₂O₄. XPS: X-ray photoelectron spectroscopy; PANI: polyaniline.