Nitrogen-Doped Porous Carbon Derived from Malachium Aquaticum Biomass as a Highly Efficient Electrocatalyst for Oxygen Reduction Reaction

In this work, N-doped porous carbon materials are synthesized from natural biomass (malachium aquaticum). The as-prepared sample with high Brunauer-Emmett-Teller surface area (851.41 m2 g−1) possesses excellent oxygen reduction reaction (ORR) performance. Its onset potential is higher (about 10 mV) than that of Pt/C, and more interestingly, the current density is almost double that of Pt/C. Besides, the tolerance to methanol and stability of the as-prepared sample is also superior to those of Pt/C. The excellent performance is probably due to the balance of 3D structure, rich active sites, superior electrical conductivity, especially the superhydrophilicity, which originates from the roughness and hydrophilic functional groups on the surface and facilitates the deep wetting by the electrolyte into the micro/nano-scale pores, and enables more oxygen have the opportunity to contact the catalyst. Our study further rationalizes such method to prepare functional carbon materials using environmental biomass waste as precursors with practical applications in electrochemistry.

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