Fig. 2: Surface oxidation state of Co2FeO4 and CoFe2O4 during OER.
From: 3D atomic-scale imaging of mixed Co-Fe spinel oxide nanoparticles during oxygen evolution reaction
X-ray photoelectron spectra of a, b Co 2p and c, d Fe 2p levels of Co2FeO4 and CoFe2O4 in the pristine state and after 100, 500 and 1000 cycles. The dashed lines indicate the satellite features of Co3O4-like Co (II, III) and CoO-like Co(II). Source data are provided as a Source Data file.
