Jia Peng, Zhang Jiawei, Xia Guangmei, Yu Zhenjiang, Sun Jiazhen, Ji Xingxiang
State Key Laboratory of Biobased Material and Green Papermaking, Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education/Shandong Province, Faculty of Light Industry, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
Polymers (Basel). 2022 Jun 25;14(13):2581. doi: 10.3390/polym14132581.
The defect and N-doping engineering are critical to developing the highly efficient metal-free electrocatalysts for oxygen reduction reaction (ORR), mainly because they can efficiently regulate the geometric/electronic structures and sur-/interface properties of the carbon matrix. Herein, we provide a facile and scalable strategy for the large-scale synthesis of N-doped porous carbon nanosheets (NPCNs) with hierarchical pore structure, only involving solvothermal and pyrolysis processes. Additionally, the turnover frequency of ORR (TOF) was calculated by taking into account the electron-transfer number (). Benefiting from the trimodal pore structures, high specific surface area, a higher pore volume, high-ratio mesopores, massive vacancies/long-range structural defects, and high-content pyridinic-N (2.1%), the NPCNs-1000 shows an excellent ORR activity (1600 rpm, = ~5.99 mA cm), a selectivity to four-electron ORR (100%) and a superior stability in both the three-electrode tests (CP test for 7500 s at 0.8 V, Δ = ~0.58 mA cm) and Zn-Air battery (a negligible loss of 0.08 V within 265 h). Besides, the experimental results indicate that the enhancement of ORR activity mainly originates from the defects and pyridinic-N. More significantly, this work is expected to realize green and efficient energy storage and conversion along with the carbon peaking and carbon neutrality goals.
缺陷和氮掺杂工程对于开发用于氧还原反应（ORR）的高效无金属电催化剂至关重要，主要是因为它们可以有效地调节碳基体的几何/电子结构以及表面/界面性质。在此，我们提供了一种简便且可扩展的策略，用于大规模合成具有分级孔结构的氮掺杂多孔碳纳米片（NPCNs），仅涉及溶剂热和热解过程。此外，通过考虑电子转移数（）来计算ORR的周转频率（TOF）。受益于三峰孔结构、高比表面积、较高的孔体积、高比例的中孔、大量空位/长程结构缺陷以及高含量的吡啶氮（2.1%），NPCNs - 1000表现出优异的ORR活性（1600 rpm，= ~5.99 mA cm）、对四电子ORR的选择性（100%）以及在三电极测试（在0.8 V下进行7500 s的恒电位测试，Δ = ~0.58 mA cm）和锌空气电池（在265 h内电压损失可忽略不计，为0.08 V）中均具有优异的稳定性。此外，实验结果表明ORR活性的增强主要源于缺陷和吡啶氮。更重要的是，随着碳达峰和碳中和目标的实现，这项工作有望实现绿色高效的能量存储和转换。
