School of Material Science and Engineering, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, People's Republic of China.
Dalton Trans. 2018 Jul 24;47(29):9724-9732. doi: 10.1039/c8dt01549j.
Three-dimensional (3D) nitrogen-doped carbon materials with a hierarchically porous structure are prepared by the introduction of nitrogen-doped carbon spheres (NCS) into the inter-sheet spaces of graphitic carbon nitride nanosheets (g-CN). The as-prepared graphitic carbon nitride/nitrogen-doped carbon sphere (g-CN/NCS) composites present a high nitrogen doping level, a unique hierarchically porous structure, and a high specific surface area of 448 m2 g-1. Such particular features make the g-CN/NCS composite an ideal material for supercapacitor electrodes, which could deliver a large specific capacitance of 403.6 F g-1 at 0.1 A g-1, an excellent rate capability of 220 F g-1 at 10 A g-1, and a high cycling stability with almost 100% capacitance retention after 5000 cycles at 20 A g-1. Furthermore, the g-CN/NCS electrode-based symmetric supercapacitors exhibit a decent energy density of 6.75 W h kg-1 at a power density of 1000 W kg-1. The enhanced performances are mainly attributed to the high nitrogen doping level and the hierarchically porous structure of the 3D structured g-CN/NCS composites, which provide an efficient pathway for transporting ions and electrons, and endow more active sites for electrochemical energy storage.
通过将氮掺杂碳球（NCS）引入石墨相氮化碳纳米片（g-CN）的层间空间，制备了具有分级多孔结构的三维（3D）氮掺杂碳材料。所制备的石墨相氮化碳/氮掺杂碳球（g-CN/NCS）复合材料具有高氮掺杂水平、独特的分级多孔结构和 448 m2 g-1 的高比表面积。这些特殊的特性使 g-CN/NCS 复合材料成为超级电容器电极的理想材料，在 0.1 A g-1 时可提供 403.6 F g-1 的大比电容、在 10 A g-1 时具有出色的倍率性能（220 F g-1），并且在 20 A g-1 下循环 5000 次后电容保持率几乎为 100%，具有高循环稳定性。此外，基于 g-CN/NCS 电极的对称超级电容器在 1000 W kg-1 的功率密度下表现出 6.75 W h kg-1 的相当能量密度。性能的提高主要归因于 3D 结构的 g-CN/NCS 复合材料的高氮掺杂水平和分级多孔结构，这为离子和电子的传输提供了有效的途径，并赋予了更多的电化学储能活性位点。
