以Ti2AlC粉为原料,采用HCl+Li F腐蚀剂一步腐蚀-插层制备出了Ti2CTx MXene,进一步通过超声处理得到了剥离的单层或少层的Ti2CTx MXene。研究了腐蚀温度对腐蚀效率和剥离率的影响。结果表明,提高腐蚀温度可显著提高Ti2AlC母相向Ti2CTx MXene的转化率,但由于腐蚀形成的Ti2C层表面氧化随之加重,故剥离率随腐蚀温度的升高呈先增大后减小的变化。40℃腐蚀得到的样品的剥离率最高为18%,对应的Ti2CTx纳米片悬浮液浓度约为0.36 mg/m L,Ti2CTx纳米片的厚度约为1 nm,无明显缺陷。剥离的Ti2CTxMXene用作锂离子电池负极表现出了较高的容量和良好的倍率性能。在100 m A·g^(-1)、300 m A·g^(-1)、1000 m A·g^(-1)电流密度下稳定的放电比容量分别为352 m Ah·g^(-1)、245 m Ah·g^(-1)、169 m Ah·g^(-1),是用HF工艺合成的Ti2CTx MXene的2倍。
Herein,exfoliation and delamination of two-dimensional( 2D) Ti2CTxMXene using etchant of HCl + Li F,in which both etching and intercalation were achieved in exfoliation process,were thoroughly investigated with the focus of reaction temperature. The results suggest that increasing etching temperature promotes the exfoliation process,i. e.,the transformation from Ti2 Al C to multilayer Ti2CTxMXene,whereas the delamination ratio increases firstly and then decreases with the increasing temperature,and the samples etched at 40 ℃ show the highest delamination ratio of 18%( corresponding to a suspension concentration of Ti2CTx MXene flakes as high as 0. 36 mg / m L). The prepared MXene flakes,about 1 nm thick,contained no obvious nanometer sized defects. As anode for lithium ion batteries,the delaminated Ti2CTxMXene show high capacity and good cycling behavior,and obtained specific capacities of 352 m Ah·g~(-1),245 m Ah·g~(-1),169 m Ah·g~(-1)respectively at the current density of 100 m A·g~(-1),300 m A·g~(-1),1000 m A·g~(-1),twice to those of the Ti2CTxMXene prepared by conventional HF process.