Zhang Shunlong, Ying Hangjun, Huang Pengfei, Wang Jianli, Zhang Zhao, Yang Tiantian, Han Wei-Qiang
School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
ACS Nano. 2020 Dec 22;14(12):17665-17674. doi: 10.1021/acsnano.0c08770. Epub 2020 Dec 10.
MXenes have been widely explored in energy storage because of their extraordinary properties; however, the majority of research on their application was staged at multilayered MXenes or assisted by carbon materials. Scientifically speaking, the two most distinctive properties of MXenes are usually neglected, composed of large interlayer spacing and abundant surface chemistry, which distinguish MXenes from other two-dimensional materials. Herein, few-layered MXene (f-MXene) nanosheet powders can be easily prepared according to the modified solution-phase flocculation method, completely avoiding the restacking phenomenon of f-MXene nanosheets in preparation and oxidation issues during the storage process. further employing the solvothermal reaction and annealing treatment, we successfully constructed pillared SnS/TiCT composites decorated with formed TiO nanoparticles. In the composites, MXenes can play the role of a conductive network, a buffer matrix for volume expansion of SnS, while the active SnS nanoplates can fully deliver the advantage of high capacity and further induce interlayer engineering of TiCT during cycling. As a result, the pillared SnS/TiCT MXene composites exhibit obvious improvement in electrochemical performance. Interestingly, there is an apparent enhancement of capacity at succedent cycling, which can be ascribed to the "pillar effect" of TiCT MXenes. The efforts and attempts made in this work can further broaden the development of pillared MXene composites.
由于其卓越的性能,MXenes在能量存储领域已得到广泛研究;然而,大多数关于其应用的研究是在多层MXenes上进行的,或者是在碳材料的辅助下进行的。从科学角度讲,MXenes最显著的两个特性通常被忽视了,即其具有较大的层间距和丰富的表面化学性质,这使得MXenes有别于其他二维材料。在此,通过改进的溶液相絮凝法可以轻松制备出少层MXene(f-MXene)纳米片粉末,完全避免了f-MXene纳米片在制备过程中的重新堆叠现象以及储存过程中的氧化问题。进一步采用溶剂热反应和退火处理,我们成功构建了负载有TiO纳米颗粒的柱状SnS/TiCT复合材料。在该复合材料中,MXenes可充当导电网络以及SnS体积膨胀的缓冲基体,而活性SnS纳米片则能充分发挥其高容量优势,并在循环过程中进一步引发TiCT的层间工程。结果,柱状SnS/TiCT MXene复合材料的电化学性能有了明显提升。有趣的是,在后续循环中容量有明显增强,这可归因于TiCT MXenes的“柱状效应”。这项工作所做的努力和尝试能够进一步拓宽柱状MXene复合材料的发展。