fig2
Figure 2. Structural characterization. (A and B) Co 2p XPS spectra of CoOOH-FeD-CoV and the compared cactalysts; (C) O 1s and (D) Fe 2p XPS spectra of CoOOH-FeD-CoV and the compared catalysts; (E) O K-edge NEXAFS spectra of CoOOH-FeD-CoV and CoOOH-FeD following the OER activation process; (F) EPR spectra of different catalysts after electrochemical testing, measured at 10 K. OER: Oxygen evolution reaction; XPS: X-ray photoelectron spectroscopy; NEXAFS: near-edge X-ray absorption fine structure; EPR: electron paramagnetic resonance.








