Yang Ben, She Yin, Zhang Changgeng, Kang Shuai, Zhou Jin, Hu Wei
Key Laboratory of Optoelectronic Technology and System of Ministry of Education, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, China.
Key Laboratory of Fundamental Science Micro/Nano Device System Technology, Micro System Research Center of Chongqing University, Chongqing 400044, China.
Nanomaterials (Basel). 2020 Feb 18;10(2):345. doi: 10.3390/nano10020345.
Layered two-dimensional titanium carbide (TiCT), as an outstanding MXene member, has captured increasing attention in supercapacitor applications due to its excellent chemical and physical properties. However, the low gravimetric capacitance of TiCT restricts its rapid development in such applications. Herein, this work demonstrates an effective and facile hydrothermal approach to synthesize nitrogen doped intercalation TiO/TiN/TiCT with greatly improved gravimetric capacitance and excellent cycling stability. The hexamethylenetetramine (CHN) in hydrothermal environment acted as the nitrogen source and intercalants, while the TiCT itself was the titanium source of TiO and TiN. We tested the optimized nitrogen doped intercalation TiO/TiN/TiCT electrodes in HSO, LiSO, NaSO, LiOH and KOH electrolytes, respectively. The electrode in HSO electrolyte delivered the best electrochemical performance with high gravimetric capacitance of 361 F g at 1 A g and excellent cycling stability of 85.8% after 10,000 charge/discharge cycles. A systematic study of material characterization combined with the electrochemical performances disclosed that TiO/TiN nanoparticles, the introduction of nitrogen and the NH intercalation efficaciously increased the specific surface areas, which is beneficial for facilitating electrolyte ions transportation. Given the excellent performance, nitrogen doped intercalation TiO/TiN/TiCT bodes well as a promising pseudocapacitor electrode for energy storage applications.
层状二维碳化钛（TiCT）作为一种出色的MXene成员，因其优异的化学和物理性质，在超级电容器应用中受到了越来越多的关注。然而，TiCT的低质量比电容限制了其在此类应用中的快速发展。在此，这项工作展示了一种有效且简便的水热方法，用于合成具有大大提高的质量比电容和优异循环稳定性的氮掺杂插层TiO/TiN/TiCT。水热环境中的六亚甲基四胺（CHN）充当氮源和插层剂，而TiCT本身则是TiO和TiN的钛源。我们分别在HSO、LiSO、NaSO、LiOH和KOH电解质中测试了优化后的氮掺杂插层TiO/TiN/TiCT电极。在HSO电解质中的电极表现出最佳的电化学性能，在1 A g下具有361 F g的高质量比电容，在10000次充放电循环后具有85.8%的优异循环稳定性。结合电化学性能对材料表征进行的系统研究表明，TiO/TiN纳米颗粒、氮的引入和NH插层有效地增加了比表面积，这有利于促进电解质离子传输。鉴于其优异的性能，氮掺杂插层TiO/TiN/TiCT有望成为一种用于储能应用的有前途的赝电容器电极。
