以Ti_2AlC粉为原料,采用HCl+Li F腐蚀剂一步腐蚀-插层制备出了Ti_2CT_x MXene,进一步通过超声处理得到了剥离的单层或少层的Ti_2CT_x 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Ti_2AlC母相向Ti_...以Ti_2AlC粉为原料,采用HCl+Li F腐蚀剂一步腐蚀-插层制备出了Ti_2CT_x MXene,进一步通过超声处理得到了剥离的单层或少层的Ti_2CT_x 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Ti_2AlC母相向Ti_2CT_x 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Ti_2CT_x纳米片悬浮液浓度约为0.36 mg/m L,Ti_2CT_x纳米片的厚度约为1 nm,无明显缺陷。剥离的Ti_2CT_xMXene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Ti_2CT_x MXene的2倍。展开更多
We prepared a two-dimensional transition metal carbide Ti_2CT_x by treatment of Ti_2 AlC in molten fluoride salt. Two fluorinated salt systems were used to etch Al from Ti_2 AlC powder precursor under the argon atmosp...We prepared a two-dimensional transition metal carbide Ti_2CT_x by treatment of Ti_2 AlC in molten fluoride salt. Two fluorinated salt systems were used to etch Al from Ti_2 AlC powder precursor under the argon atmosphere, and then the resulting MXene was delaminated with TBAOH to produce few-layered nanosheets of Ti_2CT_x. The reaction was undergone at different temperatures to study the effect of temperature.The results show that the optimal reaction temperature is 600 ℃ in LiF-NaF-KF system, and 850 ℃ in NaFKF system. The molten salt treated products are delaminated and quasi-2 D MXene sheets can be obtained. The thickness of the MXene sheets prepared from the binary molten salt system is smaller than that of the ternary molten salt system.展开更多
Two-dimensional(2D)metal carbides,MXene,present the promising application for the energy storage system.Among the MXene family,Ti_2CT_xas the lightest material,shows its unique electrochemical performance.Herein,Ti_2C...Two-dimensional(2D)metal carbides,MXene,present the promising application for the energy storage system.Among the MXene family,Ti_2CT_xas the lightest material,shows its unique electrochemical performance.Herein,Ti_2CT_xis synthesized by selective etching Al layer from the Ti_2Al C.With the optimized HF treating condition,Ti_2CT_xdisplays high volumetric capacitance and remarkable rate ability.Moreover,the Ti_2CT_x//Ti_2CT_xsymmetric supercapacitor is designed and assembled,which presents capable capacitance,outstanding rate performance and excellent cycling performance.The remarkable electrochemical performance is attributed to its 2D structure and high electronic conductivity.This work demonstrates the potential application of the Ti_2CT_xfor the supercapacitors and provides a template to design highperformance supercapacitors with 2D electrode materials.展开更多
文摘以Ti_2AlC粉为原料,采用HCl+Li F腐蚀剂一步腐蚀-插层制备出了Ti_2CT_x MXene,进一步通过超声处理得到了剥离的单层或少层的Ti_2CT_x 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Ti_2AlC母相向Ti_2CT_x 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Ti_2CT_x纳米片悬浮液浓度约为0.36 mg/m L,Ti_2CT_x纳米片的厚度约为1 nm,无明显缺陷。剥离的Ti_2CT_xMXene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Ti_2CT_x MXene的2倍。
基金Funded by the Foundation for Hubei Provincial Key Laboratory of Green Materials for Light Industry(Nos.201710A15)
文摘We prepared a two-dimensional transition metal carbide Ti_2CT_x by treatment of Ti_2 AlC in molten fluoride salt. Two fluorinated salt systems were used to etch Al from Ti_2 AlC powder precursor under the argon atmosphere, and then the resulting MXene was delaminated with TBAOH to produce few-layered nanosheets of Ti_2CT_x. The reaction was undergone at different temperatures to study the effect of temperature.The results show that the optimal reaction temperature is 600 ℃ in LiF-NaF-KF system, and 850 ℃ in NaFKF system. The molten salt treated products are delaminated and quasi-2 D MXene sheets can be obtained. The thickness of the MXene sheets prepared from the binary molten salt system is smaller than that of the ternary molten salt system.
基金financially supported by the National Natural Science Foundation of China (51702063)Ministry of Science and Technology of China (No. 2015CB251103)+2 种基金the Science & Technology Department of Jilin Province (No. 20140520093JH)the Open Project of State Key Laboratory of Superhard Materials (Jilin University, No. 201513)the Fundamental Research Funds for the Central Universities (No. GK2100260182)
文摘Two-dimensional(2D)metal carbides,MXene,present the promising application for the energy storage system.Among the MXene family,Ti_2CT_xas the lightest material,shows its unique electrochemical performance.Herein,Ti_2CT_xis synthesized by selective etching Al layer from the Ti_2Al C.With the optimized HF treating condition,Ti_2CT_xdisplays high volumetric capacitance and remarkable rate ability.Moreover,the Ti_2CT_x//Ti_2CT_xsymmetric supercapacitor is designed and assembled,which presents capable capacitance,outstanding rate performance and excellent cycling performance.The remarkable electrochemical performance is attributed to its 2D structure and high electronic conductivity.This work demonstrates the potential application of the Ti_2CT_xfor the supercapacitors and provides a template to design highperformance supercapacitors with 2D electrode materials.
