Modified two-step etching method for the synthesis of Ti3C2 MXene with enhanced electrochemical performance
Pei Zhang, Kexin Wang, Haixiang Wang, Dingxiong Tan, Cuicui Wang, Xiaohua Zhang, Jianfeng Zhu
Abstract
This work presents a modified etching method for the synthesis of Ti3C2 MXene. The process involves two steps: washing Ti3AlC2 with a low concentration of HF and etching Ti3AlC2 with varying concentrations of FeCl3. FeCl3 can etch the Al layers of Ti3AlC2 by a metal displacement reaction at room temperature, resulting in Ti3C2 nanosheets with an accordion-like morphology. The obtained Ti3C2 MXene was tested as a working electrode for supercapacitors, achieving a maximum specific capacitance of 213.2 F/g at 0.5 A/g in a 6M KOH electrolyte solution, which is higher than that of a Ti3C2 electrode without modification. The method is simple, efficient and reduces the use of HF. This work shows the possibility of synthesizing various MXene-based frameworks using metallic cations with higher redox potentials.