Nitrogen-doped carbon materials are deemed promising cathode catalysts for microbial fuel cells (MFCs). The challenge lies in reducing costs and enhancing the proportion of electrocatalytically active nitrogenous functional groups. This study proposes a hydrothermal-mediated in-situ doping method to produce nitrogen-doped biochar from aquatic plants. The nitrogen atoms are anchored in the carbon structure during hydrothermal treatment. Subsequent pyrolysis converts the hydrochar into a catalyst with highly catalytically active aromatic ring structure (HC-N+PY). The as-prepared HC-N+PY electrocatalyst demonstrates superior oxygen reduction reaction activity with half-wave potentials of 0.82 V. The MFC with HC-N+PY exhibits excellent performance, with a peak power density of 1444 mW/m2. Theoretical calculations demonstrate that the synergistic effect of graphitic nitrogen and C–O groups at defect sites enhances O2 adsorption and protonation. This work highlights the potential of utilizing nitrogen-doped biochar derived from aquatic plants as an effective catalyst for enhancing the performance of microbial fuel cells.

中文翻译：

---

水热介导的原位氮掺杂制备生物炭以增强微生物燃料电池中的氧还原反应


氮掺杂碳材料被认为是有前途的微生物燃料电池 （MFC） 阴极催化剂。挑战在于降低成本和提高电催化活性含氮官能团的比例。本研究提出了一种水热介导的原位掺杂方法，从水生植物中生产氮掺杂生物炭。在水热处理过程中，氮原子锚定在碳结构中。随后的热解将 hydrochar 转化为具有高催化活性芳香环结构 （HC-N+PY） 的催化剂。所制备的 HC-N+PY 电催化剂表现出优异的氧还原反应活性，半波电位为 0.82 V。采用 HC-N+PY 的 MFC 表现出优异的性能，峰值功率密度为 1444 mW/m2。理论计算表明，石墨氮和 C-O 基团在缺陷部位的协同作用增强了 O2 的吸附和质子化。这项工作强调了利用来自水生植物的氮掺杂生物炭作为增强微生物燃料电池性能的有效催化剂的潜力。