Preparation and characterization of nano spinels for electrocatalysis of oxygen evolution in alkaline solutions

Some new nano-sized ternary ferrites with molecular formula, CuFe 2 - x Cr x O 4 ( 0 ⩽ x ⩽ 1 ) have been prepared by a precipitation method and were investigated as electrocatalysts for the oxygen evolution reaction (OER) in alkaline solutions. The reaction followed first-order kinetics with respect to OH - concentration, regardless of the nature of the electrocatalyst. The Tafel slope for the OER was ∼ 2.3 RT / F with each oxide at low overpotentials. The replacement of Fe by Cr in the CuFe2O4 matrix was found to improve both geometrical as well as electronic properties of the material in favour of electrocatalysis of O2 evolution considerably.