Tu Kejun, Zou Lingyi, Yang Chongqing, Su Yuezeng, Lu Chenbao, Zhu Jinhui, Zhang Fan, Ke Changchun, Zhuang Xiaodong
School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
The Meso-Entropy Matter Lab, School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
Chemistry. 2020 May 20;26(29):6525-6534. doi: 10.1002/chem.201904769. Epub 2020 Jan 28.
Two-dimensional (2D) porous carbon nanosheets (2DPCs) have attracted great attention for their good porosity and long-distance conductivity. Factors such as templates, precursors, and carbonization-activation methods, directly determine their performance. However, rational design and preparation of porous carbon materials with controlled 2D morphology and heteroatom dopants remains a challenge. Therefore, an ionic polyimide with both sp - and sp -hybridized nitrogen atoms was prepared as a precursor for fabricating N-doped hexagonal porous carbon nanosheets through a hard-template approach. Because of the large surface area and efficient charge-mass transport, the resulting activated 2D porous carbon nanosheets (2DPCs-a) displayed promising electrocatalytic properties for oxygen reduction reaction (ORR) in alkaline and acidic media, such as ultralow half-wave potential (0.83 vs. 0.84 V of Pt/C) and superior limiting current density (5.42 vs. 5.14 mA cm of Pt/C). As air cathodes in Zn-air batteries, the as-developed 2DPCs-a exhibited long stability and high capacity (up to 614 mA h g ), which are both higher than those of commercial Pt/C. This work provides a convenient method for controllable and scalable 2DPCs fabrication as well as new opportunities to develop high-efficiency electrocatalysts for ORR and Zn-air batteries.
二维（2D）多孔碳纳米片（2DPCs）因其良好的孔隙率和长距离导电性而备受关注。模板、前驱体和碳化-活化方法等因素直接决定了它们的性能。然而，合理设计和制备具有可控二维形态和杂原子掺杂的多孔碳材料仍然是一个挑战。因此，制备了一种同时含有sp和sp杂化氮原子的离子型聚酰亚胺，作为通过硬模板法制备氮掺杂六方多孔碳纳米片的前驱体。由于具有大表面积和高效的电荷-质量传输，所得的活化二维多孔碳纳米片（2DPCs-a）在碱性和酸性介质中对氧还原反应（ORR）表现出有前景的电催化性能，如超低半波电位（相对于Pt/C为0.83对0.84 V）和优异的极限电流密度（相对于Pt/C为5.42对5.14 mA cm）。作为锌空气电池中的空气阴极，所开发的2DPCs-a表现出长稳定性和高容量（高达614 mA h g），两者均高于商业Pt/C。这项工作为可控且可扩展的2DPCs制备提供了一种便捷方法，也为开发用于ORR和锌空气电池的高效电催化剂提供了新机遇。
