Efficacious Electrochemical Oxygen Evolution from Novel Co (II) Porphyrin-Pyrene based Conjugated Microporous Polymer.

Oxygen evolution reaction (OER) is energetically challenging from the platform of making many photovoltaic devices such as metal-Air battery and water splitting systems, because of its poor kinetics even when precious metals are used. Herein a Co (II)-porphyrin/pyrene comprised conjugated microporous polymer Co-MPPy-1 has been developed which shows efficient oxygen evolution reaction in alkaline medium. The material was characterized by FT-IR, solid-state 13C CP-MAS NMR, N2 volumetric adsorption/desorption analysis, SEM, UHR-TEM, XPS, and other physical studies. Co-MPPy-1 showed Brunauer- Emmett-Teller (BET) surface area of ~ 501 m2 g-1. Co-MPPy-1 achieved a current density of 1 mA cm-2 and 10 mA cm-2 at 340 mV and 420 mV respectively. The turnover frequency (TOF) calculated for the OER is 0.43 sec-1. The heterogeneity of this electrocatalyst was tested by chronoamperometric measurement and 1000 cycle recyclability test with retainment of the excellent electrochemical catalytic activity. This can be attributed to the presence of high density of Co (II) porphyrin unit and efficient charge transport in the π-conductive conjugated polymeric backbone.