二维Ti3C2Tx MXene材料的制备与工艺优化

二维（2D）过渡金属碳/氮化物（MXene）材料是当前最受关注的二维材料之一，其中二维碳化钛（Ti₃C₂T_x MXene）材料的研究最为广泛。该材料目前主要通过刻蚀三元碳化物或氮化物（MAX相）后进一步插层得到，因此MAX相材料的纯度和制备工艺条件直接决定了Ti₃C₂T_x MXene材料的物化性质。主要完成了不同Ti₃AlC₂ MAX相材料的筛选，选择氢氟酸（HF）刻蚀，并优化了不同的插层方法，制备了一系列Ti₃C₂T_x MXene材料。通过X射线衍射（XRD）、场发射扫描电镜（FESEM）、透射电子显微镜（TEM）、原子力显微镜（AFM）和X射线光电子能谱（XPS）等表征，确定使用原位锂离子（Li⁺）插层法可有效获得单层Ti₃C₂T_x MXene材料。制备的单层Ti₃C₂T_x MXene材料的表面平整，片径约为150 nm，厚度约为2 nm。同时，创新性地采用涡旋震荡辅助材料分层，极大地缩短了超声时间，提高了单层Ti₃C₂T_x MXene材料的产率（可达70%），并且可以避免材料氧化，为Ti₃C₂T_x MXene材料未来应用提供了新方法。

Preparation and process optimization of 2D Ti3C2Tx MXene material

Recently,two-dimensional (2D) transition metal carbon/nitride (MXene) material attracts much attention,especially for Ti₃C₂T_x MXene material.Single-layer Ti₃C₂T_x MXene is usually obtained by etching or intercalation approach.Accordingly,the purity and preparation technology of MAX phase directly determine the physico-chemical properties of Ti₃C₂T_x MXene.Herein,several different Ti₃AlC₂ MAX phase materials were chosen as the precursors and gave a series of Ti₃C₂T_x MXene by using hydrofluoric acid etching technology with X-ray diffraction (XRD),field emission scanning electron microscope (FESEM),transmission electron microscopy (TEM),atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS).We found that Ti₃C₂T_x MXene with uniform single-layer structure can be prepared by using in-situ lithium ion(Li⁺) intercalation method.It had a flat surface with a sheet diameter of about 150 nm and a thickness of about 2 nm.Moreover,a novel vortex shaking approach was developed,which can save ultrasonic time,enhance the yield of Ti₃C₂T_x MXene(up to 70%),and avoid oxidation of Ti₃C₂T_x MXene.