Fluorine‐Free Synthesis of High‐Purity Ti 3 C 2 T x (T=OH, O) via Alkali Treatment

作者：Tengfei Li, Lulu Yao, Qinglei Liu, Jiajun Gu, Ruichun Luo, Jinghan Li, Xudong Yan, Weiqiang Wang, Pan Liu, Bin Chen, Wang Zhang, Waseem Abbas, Raheela Naz, Di Zhang · 发表于：Angewandte Chemie International Edition · 年份：2018 · DOI：10.1002/anie.201800887 · 被引用次数：1452 · 研究领域：MXene and MAX Phase Materials、Advancements in Battery Materials、Inorganic Chemistry and Materials

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 3 C 2 T x (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 3 C 2 T x with ca. 92 wt % in purity (using 27.5 m NaOH, 270 °C). Without the F terminations, the resulting Ti 3 C 2 T x film electrode (ca. 52 μm in thickness, ca. 1.63 g cm −3 in density) is 314 F g −1 via gravimetric capacitance at 2 mV s −1 in 1 m H 2 SO 4 . This surpasses (by ca. 214 %) that of the multilayer Ti 3 C 2 T x 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.