Hybrid cobalt phthalocyanine polymer as a potential electrocatalyst for hydrogen evolution reaction

Abstract

In this work, simple, novel, eco-friendly, low-cost and highly-active cobalt oxytyramine phthalocyanine polymer, poly[CoOTPc] is synthesized and characterized with various spectro-analytical techniques to demonstrate the successful construction of poly[CoOTPc]. In order to enhance the conductivity and electrocatalytic performance of poly[CoOTPc], an organic-hybrid composite with Ketjen-Black (KB) is prepared in different ratios and their activity was assessed towards hydrogen evolution reaction (HER). The linear sweep voltammogram of organic-hybrid composite (3.5:1.5 ratio of polymer to KB) exhibited least overpotential of −79 mV at −10 mA cm−2 current density towards HER in 0.5 M H2SO4 with a Tafel slope closer to the standard catalyst (Pt/C) both in lower and higher overpotentials. In addition, lower charge-transfer resistance is noticed at the hybrid catalyst and is comparable with the standard catalyst suggesting that the designed poly[CoOTPc]+KB organic-hybrid composite is one of the superior, low-cost electrocatalyst towards HER with excellent stability and efficiency for the large-scale integrated green energy systems.