<span style="font-size:14.0pt;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-US;mso-fareast-language: EN-US;mso-bidi-language:AR-SA">Electrocatalytic properties of spinel type Ni_xFe_3-xO₄ synthesized at low temperature for oxygen evolution in KOH solutions</span>

Abstract

<span style="font-size:14.0pt;font-family:" times="" new="" roman";="" mso-fareast-font-family:"times="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">Some nickel-substituted ferrites (Ni_xFe_3-xO₄, where x =0.25, 0.5, 1.0, 1.5) obtained at low temperature in the form of films on nickel supports have been investigated as electrocatalysts for the oxygen evolution reaction in alkaline solution. The true electrocatalytic activity of the oxide is greatly increased by increasing the nickel substitution, being highest with 1.0 mole Ni. The electrolytic evolution of O₂ follows approximately second-order kinetics in OH^- ion concentration. The Tafel slope values for the reaction at different catalytic films are approximately the same (i.e., <span style="font-size:14.0pt;font-family:Arial;mso-fareast-font-family:" times="" new="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">41-47 <span style="font-size:14.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="">mV decade^-1). The catalysts prepared <i>in situ </i>have been observed to be electrocatalytically much more active than those of similar oxides prepared by other methods.</span></span></span>