Fluorine‐Free Synthesis of High‐Purity Ti3C2Tx (T=OH, O) via Alkali Treatment. Issue 21 (25th April 2018)

• Record Type: Journal Article
• Authors: 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
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 21(2018)
• Page Start: 6115
• Page End: 6119
• Publication Date: 2018-04-25
• Subjects: hydrothermal synthesis -- MXenes -- supercapacitors -- titanium -- two-dimensional materials; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201800887
• Languages: English
• ISSNs: 1433-7851

Abstract

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 Ti3 C2 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 Ti3 C2 T x with ca. 92 wt % in purity (using 27.5 m NaOH, 270 °C). Without the F terminations, the resulting Ti3 C2 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 H2 SO4 . This surpasses (by ca. 214 %) that of the multilayer Ti3 C2 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. Abstract : High‐purity (92 wt %) Ti3 C2 T x (T=OH, O) is obtained by an alkali‐assisted hydrothermal route that is totally free of HF. The obtained Ti3 C2 T x terminated with OH/O shows a gravimetric capacitance (314 F g −1 ) that surpasses its HF‐etched counterparts by about 214 %. This method provides an alkali‐etching strategy for MXenes in which the interlayer amphoteric/acidic atoms from the pristine MAX phase must be removed.