A mononuclear cobalt complex for water oxidation: new controversies and puzzles.

Herein the role of a mononuclear cobalt(iii) complex, [CoIII(DPKOH)2]ClO4 (DPK = di(2-pyridyl)ketone), in the water electrooxidation process is investigated with scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction studies, NMR, chronoamperometry, cyclic voltammetry, extended X-ray absorption fine structure and X-ray absorption near edge structure determination. Our experiments show that, in comparison to the reported literature, other cobalt-containing structures on the surface of the FTO electrode could also be the true catalyst for water oxidation.