Abstract The N, P dual-doped hierarchically porous graphitic biocarbons were prepared via a simple pyrolysis of the precursors derived from hydrothermal treatment of natural polymer chitosan and triphenyl phosphine (P(Ph)3). The characterization using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption analysis indicated the samples doping with P exhibited smaller crystal size and more defect sites. The electrocatalytic activities of the as-prepared samples were evaluated with oxygen reduction reaction (ORR) in alkaline media. The results showed that the catalytic properties of N, P dual-doped samples were greatly enhanced compared with the phosphorous free ones. The optimized catalysts exhibited nearly equivalent catalytic performances to the commercial Pt/C (20%) with respect to onset potential, halfwave potential and limit current density.

中文翻译：

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氮/磷双掺杂分级多孔石墨生物碳在碱性介质中显着提高氧还原反应性能

摘要 通过对天然聚合物壳聚糖和三苯基膦 (P(Ph)3) 水热处理得到的前体进行简单的热解，制备了 N, P 双掺杂的分级多孔石墨生物碳。使用扫描电子显微镜 (SEM)、透射电子显微镜 (TEM)、X 射线衍射 (XRD)、X 射线光电子能谱 (XPS) 和 N2 吸附-解吸分析的表征表明，掺杂 P 的样品表现出较小的晶体尺寸和更多缺陷部位。在碱性介质中通过氧还原反应 (ORR) 评估所制备样品的电催化活性。结果表明，与不含磷的样品相比，N、P双掺杂样品的催化性能大大提高。