Ni foam-supported azo linkage cobalt phthalocyanine as an efficient electrocatalyst for oxygen evolution reaction

Oxygen evolution reaction (OER) is a multiple electron transfer process with a high activation barrier. Designing low cost, easily synthesizable catalysts with less overpotential and high intrinsic activity towards OER is of prime importance. The present work utilizes an organic macrocycle to decrease the overpotential for oxygen evolution reaction. The cobalt phthalocyanine polymer is synthesized via azo linkage by a diazotization method. The synthesized cobalt phthalocyanine is characterized by spectroscopic and analytical techniques. The cobalt phthalocyanine polymer-coated Ni foam is used as an OER catalyst that exhibits a lesser overpotential of 370 mV (+/- 2 mV) at the current density of 10 mA cm(-2). Surprisingly, the mixing of synthesized cobalt phthalocyanine polymer with the benchmark catalyst IrO2 results in an excellent OER activity with a decrease in overpotential up to 304 mV (+/- 1 mV). To the best of our knowledge, it is the best value reported so far for organic macrocyclebased OER catalysts. In addition, at the current density of 50 mA cm(-2), the overpotential for OER at MPc-modified Ni electrode was 450 mV (+/- 2 mV). The performance of the macrocycle-modified electrode is comparable with some of the advanced OER catalysts reported previously.