表面活性剂辅助插层制备二维Ti3C2Tx及其电化学性能研究

采用一种改进的方法制备了类石墨烯的Ti3C2Tx二维材料。首先采用氢氟酸刻蚀Ti3AlC2,然后向插层溶剂二甲亚砜中添加表面活性剂十六烷基三甲基溴化铵协助二甲亚砜共同插层,最后经超声处理制备Ti3C2Tx。XRD测试表明,由于表面活性剂的协助插层作用,插层剂分子更容易进入Ti3C2Tx层间,显著增加其层间距,减小层间的相互作用力,便于其剥离。氮气吸脱实验证实该方法制备的Ti3C2Tx具有更高的比表面积和孔容。电化学测试表明,由制备的Ti3C2Tx组装成的对称性电容器具有更高的比电容,在0.5 A/g电流密度下的比电容达75.0 F/g,当充电电流增加至4 A/g时,其电容维持在57.0 F/g。在1 A/g的电流密度下,经过2 500次的充放电循环后,制备的Ti3C2Tx材料的比电容为61.5 F/g,循化稳定率达87.0%。

Preparation and electrochemical performance of two-dimensional Ti3C2Tx with surfactant as ancillary intercalation agent

In this paper, the graphene-like two-dimensional Ti3C2Tx was prepared by an improved method. Firstly, Ti3AlC2 powders were etched by hydrofluoric acid, then intercalated in dimethyl sulfoxide with the assistance of the surfactant cetyl trimethyl ammonium bromide, and finally subjected to ultrasonic treatment. XRD tests showed that the intercalation agent molecules were more likely to enter the Ti3C2Tx layer due to the intercalation of the surfactant, which significantly increased the interlayer spacing and reduced the interaction between the layers, facilitating the delamination. Nitrogen adsorption and desorption experiments confirmed that the Ti3C2Tx prepared by this method exhibited a higher specific surface area and pore volume. Electrochemical tests showed that the symmetrical capacitor using Ti3C2Tx as electrode materials exhibited a higher specific capacitance, the specific capacitance at a current density of 0.5 A/g was 75.0 F/g. And when the charging current was increased to 4 A/g, its capacitance was maintained at 57.0 F/g. After 2 500 charge and discharge cycles, the specific capacitance of Ti3C2Tx material was 61.5 F/g at a current density of 1 A/g, and the capacitance retention was 87.0%.