State Key Laboratory of Metal Matrix Composites & Shanghai Key Laboratory of Electrical Insulation and Thermal Ageing, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Dongchuan Road 800, 200240 Shanghai, China.
Key Lab for Advanced Materials, Institute of Applied Chemistry, East China University of Science and Technology, 130 Meilong Road, 200237 Shanghai, China.
J Colloid Interface Sci. 2018 Apr 15;516:9-15. doi: 10.1016/j.jcis.2018.01.020. Epub 2018 Jan 6.
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 = 5.02 mA cm), 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，多孔碳纳米片及其相应的杂原子掺杂多孔碳纳米片作为能源转化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二维（2D）聚合物纳米片仍然是一个巨大的挑战。在这项工作中，设计了含噻二唑的扩展杂氮并薁卟啉作为制备无模板的独立 N/S 含聚合物纳米片（PN）的构建块。最重要的是，这种 PN 可以与过渡金属离子配位，制备含 Fe、N 和 S 的 PN-Fe。通过使用这些 PN-Fe 作为前体，在惰性条件下直接热解可以容易地制备 Fe/N/S 共掺杂多孔碳纳米片（PCN-FeNS）。PCN-FeNS 的 N 和 S 含量分别高达 6.4 at.% 和 0.8 at.%。作为概念验证，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。得益于高比表面积和丰富的掺杂特性，PCN-FeNS 表现出相对较高的半波电位低至 0.71 V，通过四电子转移机制（n=3.87 在 0.65 V），以及高扩散极限电流密度（J=5.02 mA cm），与商业贵金属基电催化剂相当。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，而且还提供了一种制备 Fe/N/S 共掺杂多孔碳纳米片的新策略，用于多功能能源相关应用。
