二维多层状Ti_3C_2T_x-MXene/聚吡咯纳米线复合材料的制备及电容性能研究

Preparation and Capacitive Property of Two-Dimensional Multilayer Ti_3C_2T_x-MXene/PPy-NW Composite Material

本文以体相材料MAX(Ti_3AlC_2)为基底,采用氢氟酸刻蚀法得到二维多层状Ti_3C_2T_x-MXene,将一维聚吡咯纳米线(polypyrrole nanowires,PPy-NW)与二维多层状Ti_3C_2T_x-MXene相结合,成功地制备出Ti_3C_2T_x-MXene/PPy-NW复合电极材料.并分别利用扫描电子显微镜(scanning electron microscope,SEM)、X-射线衍射(X-ray diffraction,XRD)、傅里叶变换红外光谱(fourier transform infrared spectroscopy,FTIR)及X射线光电子能谱(X-ray photoelectron spectroscopy,XPS)对其进行了形貌和结构表征.最后通过电化学测试表明,二维多层状Ti_3C_2T_x-MXene/PPy-NW复合电极材料在扫描速率为10 m V·s^(-1)时比电容可达374 F·g^(-1),高于纯PPy-NW(304 F·g^(-1)),当扫描速率增加至200 m V·s^(-1)时,仍可保留原比电容值的72.4%,展现出良好的倍率性能.而且在电流密度为5 A·g^(-1)下经过2000次的循环伏安实验,其电容保持率可达91.6%,具有良好的循环稳定性.总之,二维多层状Ti_3C_2T_x-MXene和一维PPy-NW的复合有效地提升了电极材料的电容性能,在电化学能源储存方面有着巨大的应用前景.

In this paper, the two-dimensional multilayered Ti3C2Tx-MXene was obtained by hydrofluoric acid etching method on the bulk phase material MAX(Ti3AlC2) substrate. The two-dimensional multilayered Ti3C2Tx-MXene/PPy-NW composite electrode materials were successfully prepared by combining the one-dimensional polypyrrole nanowires(PPy-NW) with two-dimensional multilayered Ti3C2Tx-MXene. The morphologies and compositions of the synthetic materials were characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR) and X-ray photoelectron spectroscopy(XPS). Electrochemical tests showed that Ti3C2Tx-MXene/PPy-NW composite electrode material could reach 374F·g^-1 at a scanning rate of 10mV·s^-1, which is higher than pure PPy-NW(304F·g^-1). When the scanning rate increased to 200mV·s^-1, it could still retain 72.4% of the original specific capacitance value, showing good multiplying performance. Finally, the Ti3C2Tx-MXene/PPy-NW composite electrode material still retained good cycling stability even at high current density of 5A·g^-1(91.6% capacitance retention after 2000 cycles). In summary, the composite of two-dimensional multilayered Ti3C2Tx-MXene and one-dimensional PPy-NW effectively improved the capacitance performance of electrode materials, and had great application prospect in electrochemical energy storage.