A Strategy for Synthesis of Carbon Nitride Induced Chemically Doped 2D MXene for High‐Performance Supercapacitor Electrodes
A Strategy for Synthesis of Carbon Nitride Induced Chemically Doped 2D MXene for High‐Performance Supercapacitor Electrodes
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DOI：
10.1002/aenm.201703173
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发表时间：
2018-05
影响因子：
27.8
通讯作者：
Y. Yoon;Minhe Lee;S. Kim;Garam Bae;Wooseok Song;S. Myung;Jongsun Lim;S. Lee;Tae-Hyung Zyung;K. An
中科院分区：
文献类型：
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作者：
Y. Yoon;Minhe Lee;S. Kim;Garam Bae;Wooseok Song;S. Myung;Jongsun Lim;S. Lee;Tae-Hyung Zyung;K. An
报道了一种分步策略，用于通过由聚合碳氮化物（p-C3 N4）诱导合成氮掺杂的2D Ti 2CTx来提高超级电容器电极的电容，所述聚合碳氮化物（p-C3 N4）同时充当氮源和插层剂。NH 2CN（氨腈）可以在500-700 °C下通过缩合反应在Ti 2CTx纳米片的表面上形成p-C3 N4。然后对p-C3 N4和Ti 2CTx复合物进行热处理以获得氮掺杂的Ti 2CTx纳米片。基于三嗪的p-C3 N4在700 °C以上分解;因此，氮物质可以在900 °C下确实地掺杂到Ti 2CTx纳米片的内部碳层和/或缺陷位点中。Ti 2CTx的扩展层间距离和c晶格参数（c-LP为28.66 Å）证明，层间生长的p-C3 N4在掺杂过程中使Ti 2CTx纳米片分层。此外，在Ti 2CTx中掺杂15.48%的氮改善了电化学性能和储能能力。由于分层结构和杂原子组成的协同作用，N掺杂的Ti 2CTx显示出作为电化学电容器电极的优异特性，例如完美的矩形循环伏安结果（CV，R2 = 0.9999），高电容（在1 A g−1时为327 F g− 1，比原始Ti 2CTx增加了140%），以及在高电流密度（5A g-1）下稳定的长循环性能（5000次循环后96.2%的电容保持率）。
A step‐by‐step strategy is reported for improving capacitance of supercapacitor electrodes by synthesizing nitrogen‐doped 2D Ti2CTx induced by polymeric carbon nitride (p‐C3N4), which simultaneously acts as a nitrogen source and intercalant. The NH2CN (cyanamide) can form p‐C3N4 on the surface of Ti2CTx nanosheets by a condensation reaction at 500–700 °C. The p‐C3N4 and Ti2CTx complexes are then heat‐treated to obtain nitrogen‐doped Ti2CTx nanosheets. The triazine‐based p‐C3N4 decomposes above 700 °C; thus, the nitrogen species can be surely doped into the internal carbon layer and/or defect site of Ti2CTx nanosheets at 900 °C. The extended interlayer distance and c‐lattice parameters (c‐LPs of 28.66 Å) of Ti2CTx prove that the p‐C3N4 grown between layers delaminate the nanosheets of Ti2CTx during the doping process. Moreover, 15.48% nitrogen doping in Ti2CTx improves the electrochemical performance and energy storage ability. Due to the synergetic effect of delaminated structures and heteroatom compositions, N‐doped Ti2CTx shows excellent characteristics as an electrochemical capacitor electrode, such as perfectly rectangular cyclic voltammetry results (CVs, R2 = 0.9999), high capacitance (327 F g−1 at 1 A g−1, increased by ≈140% over pristine‐Ti2CTx), and stable long cyclic performance (96.2% capacitance retention after 5000 cycles) at high current density (5 A g−1).