Porous carbon nanosheets and corresponding heteroatom doped porous carbon nanosheets have shown great potential as active materials for energy conversion and storage in recent years. However, it remains great challenge to prepare such kind of new two-dimensional (2D) polymer nanosheets without using any templates. In this work, thiadiazole-containing expanded heteroazaporphyrinoid was designed as the building blocks for preparation of free-standing N/S-containing polymer nanosheets (PN) without using any templates. Most importantly, such PN can coordinate with transition metal ions to prepare Fe, N, and S containing PN-Fe. By using these PN-Fe as precursors, Fe/N/S co-doped porous carbon nanosheets (PCN-FeNS) can be facilely prepared by direct pyrolysis under inert condition. The N and S contents of PCN-FeNS can reach up to 6.4 at.% and 0.8 at.%, respectively. For proof-of-concept, PCN-FeNS were further used as electrochemical catalysts for oxygen reduction reaction (ORR) in both alkaline and neutral media. Benefiting from the high surface area and rich-doping character, PCN-FeNS exhibited relatively high half-wave potential of down to 0.71 V, via a four-electron transfer mechanism (n = 3.87 at 0.65 V), as well as high diffusion limiting current density (J_L = 5.02 mA cm⁻²), which are comparable to commercial precious metal based electrocatalysts. This study not only offers a new method to prepare conjugated polymer nanosheets, but also provides a new strategy to fabricate Fe/N/S co-doped porous carbon nanosheets for versatile energy-related applications.

近年来，多孔碳纳米片和相应的杂原子掺杂的多孔碳纳米片作为能量转换和存储的活性材料显示出巨大的潜力。然而，在不使用任何模板的情况下制备这种新型的二维（2D）聚合物纳米片仍然是巨大的挑战。在这项工作中，含噻二唑的膨胀杂氮杂卟啉类化合物被设计为无需使用任何模板即可制备独立的含N / S的聚合物纳米片（PN）的基础。最重要的是，这样的PN可以与过渡金属离子配位以制备含有PN-Fe的Fe，N和S。通过使用这些PN-Fe作为前体，可以通过在惰性条件下直接热解来轻松制备Fe / N / S共掺杂多孔碳纳米片（PCN-FeNS）。PCN-FeNS的N和S含量可高达6.4 at。％和0.8 at。％，分别。为了进行概念验证，将PCN-FeNS进一步用作碱性和中性介质中氧还原反应（ORR）的电化学催化剂。得益于高表面积和富掺杂特性，PCN-FeNS通过四电子转移机制（0.65 V时的n = 3.87）表现出较低的半波电势，低至0.71V。电流密度（J_L  ＝ 5.02mA·cm ^-2），与市售的贵金属类电催化剂相当。这项研究不仅提供了一种制备共轭聚合物纳米片的新方法，而且还提供了一种新的策略来制备Fe / N / S共掺杂的多孔碳纳米片，以用于与能源相关的各种通用应用。