One‐Pot Green Process to Synthesize MXene with Controllable Surface Terminations using Molten Salts
Miao Shen, Weiyan Jiang, Kun Liang, Sufang Zhao, Rui Tang, Linjuan Zhang, Jian‐Qiang Wang
Abstract
Abstract Surface terminations of two‐dimensional MXene (Ti 3 C 2 T x ) considerably impact its physicochemical properties. Commonly used etching methods usually introduce ‐F surface terminations or metallic impurities in MXene. We present a new molten‐salt‐assisted electrochemical etching method to synthesize fluorine‐free Ti 3 C 2 Cl 2 . Using electrons as reaction agents, cathode reduction and anode etching can be spatially isolated; thus, no metallics are present in the Ti 3 C 2 Cl 2 product. The surface terminations can be in situ modified from −Cl to −O and/or −S, which considerably shortens the modification steps and enriches the variety of surface terminations. The obtained −O‐terminated Ti 3 C 2 T x are excellent electrode materials for supercapacitors, exhibiting capacitances of 225 F g −1 at 1.0 Ag −1 , good rate performance (91.1 % at 10 Ag −1 ), and excellent capacitance retention (100 % after 10000 charge/discharge cycles at 10 Ag −1 ), which is superior to multi‐layered Ti 3 C 2 T x prepared by other etching methods.