TY - GEN A1 - Indra, Arindam A1 - Menezes, Prashanth W. A1 - Das, Chittaranjan A1 - Göbel, Caren A1 - Tallarida, Massimo A1 - Schmeißer, Dieter A1 - Driess, Matthias T1 - A facile corrosion approach to the synthesis of highly active CoOxwater oxidation catalysts T2 - Journal of Materials Chemistry A N2 - Ultra-small rock salt cobalt monoxide (CoO) nanoparticles were synthesized and subjected to partial oxidation (‘corrosion’) with ceric ammonium nitrate (CAN) to form mixed-valence CoOx(1 < x< 2) water oxidation catalysts. Spectroscopic, microscopic and analytical methods evidenced a structural reformation of cubic CoO to active CoOx with a spinel structure. The superior water oxidation activity of CoOx has been established in electrochemical water oxidation under alkaline conditions. Electrochemical water oxidation with CoOx was recorded at a considerably low overpotential of merely 325 mV at a current density of 10 mA cm-2 in comparison to 370 mV for CoO. Transformation of both octahedral CoII and CoIII sites into amorphous Co(OH)2–CoOOH is the key to high electrochemical activity while the presence of a higher amount of octahedral CoIII sites in CoOx is imperative for an efficient oxygen evolution process. KW - water splitting KW - water oxidation KW - cobalt oxide catalyst KW - transmission electron microscopy (TEM) KW - X-ray photoelectron spectroscopy (XPS) KW - X-ray absorption spectroscopy (XAS) KW - Cyclic voltammetry (CV) Y1 - 2017 U6 - https://doi.org/10.1039/c6ta10650a SN - 2050-7488 SN - 2050-7496 IS - 5 SP - 5171 EP - 5177 ER -