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

摘要

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~2g~(-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 (JL = 4.95 mAcm~(-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 applicationes in energy.