Modulating Porous Carbon Electrocatalyst for Efficient Water Splitting

Abstract

The increasing public issues about the energy crisis urge the development of sustainable energy as alternatives to replace the fossil fuels. Considering the energy regeneration and environment friendly, hydrogen possesses the potential to meet the criterion of renewable and clean energies. H2 can be produced in an electrochemical water electrolyser by cathodic hydrogen evolution reaction (HER), coupled with anodic oxygen evolution reaction (OER). The kinetic barrier of both reactions require efficient electrocatalysts. However, the benchmarking electrocatalysts for HER or OER are based on precious metals, such as Pt or Ir, their high cost greatly hinders the practical H2 production from water electrolyser in an economic manner. Thus, the search of in-expensive but efficient HER and OER electrocatalysts is imminent. Among various candidature materials, low cost and high conductive carbon based nanomaterials have attracted intensive attention. Through heteroatom doping, the inert carbon nanomaterials can be activated to show promising catalytic activity. In this study, nitrogen doped nanoporous carbon electrocatalysts were obtained from thermal pyrolysis of a zinc based metal-organic framework. Cathodic treatment is successfully applied to achieve systematic modulation of the type and surface functionalities. The modulated electrocatalysts show high activity and good stability towards hydrogen and oxygen evolution in various electrolyte. Strong correlation between catalytic performance and surface chemical properties of these carbon electrocatalysts has been found. My work here paves a new way to design metal free carbon electrocatalysts for future green energy applications.