Cobalt/Nitrogen-Doped Porous Carbon Nanosheets Derived from Polymerizable Ionic Liquids as Bifunctional Electrocatalyst for Oxygen Evolution and Oxygen Reduction Reaction

Development of efficient catalysts with low cost for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) has been a long-term pursuit because of their vital role in renewable-energy technologies including fuel cells and water splitting. Herein, based on polymerizable ionic liquids (PILs) functionalized with nitrate groups as pore former and precursor of C and N, a facile one-pot thermal treatment method was developed to construct a hybrid electrocatalyst consisting of earth-abundant materials, which was made of Co-based nanoparticles (NPs) grown on 2D N-doped and macroporous carbon nanosheets (pCNs) of approximately 20-50nm thickness, that is, Co-N-pCNs. The obtained Co-N-pCNs catalyst manifests enhanced catalytic performance for both ORR and OER, even compared with the best-known commercial catalysts, such as Pt/C and IrO2. The enhanced catalytic activity arises from the 2D nanosheets and porous structures, well-dispersed Co-based NPs on the carbon sheets, the introduction of electron-rich nitrogen, and the stability by the carbon protection of Co-based NPs between the interlayers of nanosheets. Our present work supplies a novel opportunity for exploring 2D non-precious-metal catalysts for ORR and OER.