01681nas a2200169   4500008004100000022001400041245008800055210006900143260000800212300001600220490000700236520106300243100002701306700003801333700002501371856011501396       2018                        eng d  a1463-907600a Spin state engineered ZnxCo3-xO4 as an efficient oxygen evolution electrocatalyst 0 aSpin state engineered ZnxCo3xO4 as an efficient oxygen evolution  cDEC  a29452-294610 v203 aOxygen evolution is the key step in the oxidation of water in electrolyzers and photoelectrochemical cells for the production of hydrogen. Developing a non-precious metal oxide catalyst with good electrocatalytic activity for the oxygen evolution reaction (OER) is very challenging. In this work, nanostructured ZnxCo3-xO4 has been shown as an efficient catalyst with a low overpotential for the OER in 0.1 M KOH solution. Substitution of Co2+ in the spinel oxide Co3O4 with Zn2+ creates a higher number of high-spin Co3+, which is found to be directly correlated with the OER activity of ZnxCo3-xO4. Zn0.8Co2.2O4 (x = 0.8) with the optimum amount of Co2+/Co3+ and high-spin Co3+ content showed a very low overpotential of approximate to 250 mV, at 10 mA cm(-2), with a turnover frequency of approximate to 3 x 10(-3) s(-1) for the OER. The high Faradaic efficiency along with the stability of Zn0.8Co2.2O4 and electrocatalytic activity comparable with that of precious metal oxides indicate that this composition is a promising catalyst for water oxidation.1 aRamsundar, Rani, Mohan1 aPillai, Vijayamohanan, Kunjukrish1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/spin-state-engineered-znxco3-xo4-efficient-oxygen-evolution-electrocatalyst