Synthesis of Nitrogen‐Doped Hierarchical Carbon Derived from Water Hyacinth with High Catalytic Activity for Oxygen Reduction Reaction

Abstract Nitrogen‐doped carbon materials as durable high‐performance oxygen reduction reaction (ORR) catalysts showed great potential to replace Pt‐based catalysts. In this paper, a N‐self‐doped carbon catalyst is fabricated from natural biomass (water hyacinth) via a facile pyrolysis process. The as‐prepared catalysts with high specific surface area (828.50 m 2 g −1 ) possess hierarchical porous structures and excellent ORR efficiency. The catalysts exhibit a high onset potential (E onset =0.948 V), half‐wave potential (E 1/2 =0.827 V) and limiting current density (J L =4.95 mA cm −2 ), which is comparable to commercial Pt/C. Moreover, the long‐term stability and tolerance to methanol of the as‐prepared catalysts are also superior to those of Pt/C. The outstanding electrochemical performance is ascribed to the hierarchical porous structure with accessible active sites, which originated from the natural properties of water hyacinth. This work opens a new door for the synthesis of NC catalysts using biomass as a precursor. The as‐prepared catalysts have great potential for further study and applications in energy.