通过碱处理无氟合成高纯度Ti C T（T = OH，O）

Fluorine-Free Synthesis of High-Purity Ti C T (T=OH, O) via Alkali Treatment.

作者信息

Li Tengfei, Yao Lulu, Liu Qinglei, Gu Jiajun, Luo Ruichun, Li Jinghan, Yan Xudong, Wang Weiqiang, Liu Pan, Chen Bin, Zhang Wang, Abbas Waseem, Naz Raheela, Zhang Di

机构信息

State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, China.

School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.

出版信息

Angew Chem Int Ed Engl. 2018 May 22;57(21):6115-6119. doi: 10.1002/anie.201800887. Epub 2018 Apr 25.

DOI:10.1002/anie.201800887

PMID:29633442

Abstract

MXenes, 2D compounds generated from layered bulk materials, have attracted significant attention in energy-related fields. However, most syntheses involve HF, which is highly corrosive and harmful to lithium-ion battery and supercapacitor performance. Here an alkali-assisted hydrothermal method is used to prepare a MXene Ti C T (T=OH, O). This route is inspired from a Bayer process used in bauxite refining. The process is free of fluorine and yields multilayer Ti C T with ca. 92 wt % in purity (using 27.5 m NaOH, 270 °C). Without the F terminations, the resulting Ti C T film electrode (ca. 52 μm in thickness, ca. 1.63 g cm in density) is 314 F g via gravimetric capacitance at 2 mV s in 1 m H SO . This surpasses (by ca. 214 %) that of the multilayer Ti C T prepared via HF treatments. This fluorine-free method also provides an alkali-etching strategy for exploring new MXenes for which the interlayer amphoteric/acidic atoms from the pristine MAX phase must be removed.

摘要

MXenes是由层状块状材料生成的二维化合物，在能源相关领域引起了广泛关注。然而，大多数合成方法都涉及氢氟酸（HF），它具有高腐蚀性，会对锂离子电池和超级电容器的性能产生有害影响。在此，我们采用一种碱辅助水热法来制备MXene Ti₃C₂T（T=OH、O）。该方法的灵感来源于用于铝土矿精炼的拜耳法。此过程无氟，可制备出纯度约为92 wt%的多层Ti₃C₂T（使用27.5 m NaOH，270 °C）。由于没有氟端基，所得的Ti₃C₂T薄膜电极（厚度约为52 µm，密度约为1.63 g cm⁻³）在1 m H₂SO₄中，扫描速率为2 mV s⁻¹时，通过重量法测得的比电容为314 F g⁻¹。这一数值超过了通过氢氟酸处理制备的多层Ti₃C₂T（约高出214%）。这种无氟方法还为探索新型MXenes提供了一种碱蚀刻策略，对于这类新型MXenes，必须去除原始MAX相中位于层间的两性/酸性原子。