Metal-free nitrogen-doped carbon nanoribbons as highly efficient electrocatalysts for oxygen reduction reaction

Nitrogen-abundant compounds are generally regarded as perfect precursors toward in situ synthesis of nitrogen-doped carbon materials. In this study, we demonstrate a facile one-pot procedure to synthesize polyaniline-coated melamine fiber (PANI@MF) as the precursor, in which melamine fiber (MF) acts as both scaffold and nitrogen source. After high-temperature pyrolysis, wrinkled nitrogen-doped carbon nanoribbons (NCNRs) with high specific surface area (701 cm² g⁻¹) and cumulative pore volume (3.13 cm³ g⁻¹) are fabricated for electrocatalytic oxygen reduction reaction (ORR). The NCNR catalyst exhibits comparative onset potential, half-wave potential, and limiting current to those of commercial Pt/C (20 wt%, E-TEK) in alkaline media, mainly due to its high specific surface area and sufficient active sites induced by synthetic effect between nitrogen atom and carbon framework. Moreover, NCNR catalyst shows enhanced stability and high tolerance to methanol crossover effect. This study is expected to broaden new horizon to the design and fabrication of new metal-free carbon-based electrocatalyst for ORR.