A trimetallic organometallic precursor for efficient water oxidation

Abstract

Herein, we report an iron/nickel/zinc mixed oxide as a catalyst for the electrochemical water oxidation. This catalyst was synthesized by a straightforward method for the synthesis of an iron/nickel/zinc mixed oxide through the calcination of a Fe/Ni/Zn organometallic compound. The calcined product contains Fe and Ni as crucial ions for water oxidation, accompanied by the presence of Zn ions. The removal of Zn ions from the mixed oxide provides more active sites on the surface of the catalyst. The composition of the compound was characterized by some common methods and found to be an efficient water-oxidizing catalyst. The catalyst on FTO at pH = 13 yields a current density of 12 mA/cm(2) at 1.2V (vs. Ag vertical bar AgCl). After 5 hours at 1.1V, the electrode not only shows no decrease in performance, but also shows an increase from 4 to 7 mA/cm(2) in the water oxidation activity. Tafel plot, for the electrode at pH = 13 in KOH solution (0.1 M) showed linearity for the graph of Ig j vs. V with both relatively low (220.4 mV per decade) and high overpotentials (903.7 mV per decade).