Indole molecules with fused heteroaromatic structures can be adsorbed on the N-doped graphene surface through the π–π interaction. Therefore, the indole-functionalized N-doped graphene (InFGN) with mesopores is successfully fabricated by a simple hydrothermal method and subsequent vacuum freeze-drying process. The microstructure, thickness, element composition, pore structure, and electrochemical performance of InFGN are analyzed via SEM, TEM, AFM, BET, UV–vis, FT-IR, XPS, Raman, XRD, and electrochemical technologies. Since the five-membered aromatic heterocycles are electron-rich, the indole molecules fixed on the N-doped graphene surface can repair the structural defects generated by N doping. Electrochemical measurements show that the InFGN electrode highlights an excellent capacitance of 622.3 F g^–1 at 2 A g^–1 and a durable cycling life of 100.5% after 5000 charging/discharging cycle times. For further practical application, a symmetric device has been assembled by using InFGN electrodes, which realizes high-power and energy densities (18.8–20.6 Wh kg^–1 at 800–8000 W kg^–1). This study provides a shortcut for building green supercapacitors with enhanced energy storage performance.

中文翻译：

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通过非共价键将杂环分子官能化的N掺杂还原氧化石墨烯，用于高性能超级电容器。

具有稠合杂芳族结构的吲哚分子可以通过π-π相互作用吸附在N掺杂的石墨烯表面上。因此，通过简单的水热法和随后的真空冷冻干燥方法成功地制备了具有中孔的吲哚官能化的N掺杂石墨烯（InFGN）。InFGN的微观结构，厚度，元素组成，孔结构和电化学性能通过SEM，TEM，AFM，BET，UV-vis，FT-IR，XPS，拉曼，XRD和电化学技术进行了分析。由于五元芳族杂环富含电子，因此固定在N掺杂石墨烯表面的吲哚分子可以修复N掺杂产生的结构缺陷。电化学测量表明，InFGN电极具有622.3 F g ^–1的出色电容在2 A g ^–1的压力下，经过5000次充电/放电循环时间后的持久循环寿命为100.5％。为了进一步实际应用，对称设备已被装配通过使用InFGN电极，实现高功率密度和能量密度（18.8-20.6瓦千克^-1在800-8000公斤w ^ ^-1）。该研究为构建具有增强的储能性能的绿色超级电容器提供了捷径。