Li Haisheng, Xu Kui, Chen Pohua, Yuan Youyou, Qiu Yi, Wang Ligang, Zhu Liu, Wang Xiaoge, Cai Guohong, Zheng Liming, Dai Chun, Zhou Deng, Zhang Nian, Zhu Jixin, Xie Jinglin, Liao Fuhui, Peng Hailin, Peng Yong, Ju Jing, Lin Zifeng, Sun Junliang
College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China.
Key Laboratory of Flexible Electronics, and Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing 211816, China.
Natl Sci Rev. 2022 Apr 27;9(6):nwac079. doi: 10.1093/nsr/nwac079. eCollection 2022 Jun.
The effects of nanoconfined water and the charge storage mechanism are crucial to achieving the ultrahigh electrochemical performance of two-dimensional transition metal carbides (MXenes). We propose a facile method to manipulate nanoconfined water through surface chemistry modification. By introducing oxygen and nitrogen surface groups, more active sites were created for TiC MXene, and the interlayer spacing was significantly increased by accommodating three-layer nanoconfined water. Exceptionally high capacitance of 550 F g (2000 F cm) was obtained with outstanding high-rate performance. The atomic scale elucidation of the layer-dependent properties of nanoconfined water and pseudocapacitive charge storage was deeply probed through a combination of 'computational and experimental microscopy'. We believe that an understanding of, and a manipulation strategy for, nanoconfined water will shed light on ways to improve the electrochemical performance of MXene and other two-dimensional materials.
纳米限域水的作用及电荷存储机制对于实现二维过渡金属碳化物（MXenes）的超高电化学性能至关重要。我们提出了一种通过表面化学修饰来调控纳米限域水的简便方法。通过引入氧和氮表面基团，为TiC MXene创造了更多活性位点，并且通过容纳三层纳米限域水显著增加了层间距。获得了高达550 F g（2000 F cm）的超高电容以及出色的高倍率性能。通过“计算和实验显微镜”相结合的方法，深入探究了纳米限域水的层依赖性质和赝电容电荷存储的原子尺度阐明。我们相信，对纳米限域水的理解和操控策略将为改善MXene及其他二维材料的电化学性能提供思路。
