Free-base Porphyrin Polymer for Bifunctional Electrochemical Water Splitting

Projected future global energy demands require sustainable energy sources as alternatives to the current world dependence on hydrocarbon fuels. The production of hydrogen and oxygen gas from water is a promising approach. Currently, water-splitting electrolyzers require precious metals as electrocalysts because they are active and stable. Yet, replacement of these precious metals by cost-effective alternatives is necessary for the economic feasibility of this approach. Here, we describe a molecular based polymeric approach that effectively removes the need to use any metal to electrochemically split water. The incorporation of free-base porphyrin units into a 2D network structure yields a stable and efficient bifunctional electrocatalyst for water oxidation and water reduction that can operate for days at competitive overpotentials comparable to metal based ones.