Supramolecular polymers-derived nonmetal N, S-codoped carbon nanosheets for efficient oxygen reduction reaction

Abstract

The rational design and fine synthesis of highly efficient and cost-effective electrocatalysts for oxygen reduction reaction (ORR) is crucial for the wide application of fuel cells (FCs). In this work, we select a novel nitrogen and sulfur-rich supramolecular polymer as a precursor for in situ, large scale and controlled synthesis of nitrogen and sulfur dual doped carbon (N, S–C) nanosheets as a catalyst for ORR. The supramolecular polymer MTCA particles are quickly self-assembled via triple-hydrogen-bonding between melamine (M) and trithiocyanuric acid (TCA). The uniform distribution and high content of nitrogen and sulfur in the polymer is beneficial to the high and homogeneous doping in the produced self-supporting catalyst after pyrolysis. When evaluated as an electrocatalyst, the catalyst pyrolyzed at 800 °C (N, S–C/800) shows a superior ORR activity in alkaline solution. Furthermore, the N, S–C/800 catalyst exhibits superb durability and immunity towards methanol crossover. This metal-free, cost-effective and highly efficient ORR catalyst will find wide potential applications in fuel cells.