Dual-functional Ti3C2Tx MXene for wastewater treatment and electrochemical energy storage

Abstract

Multifunctional 2D materials have been exploited for highly intricate applications in engineering and medicine, including energy, bioimaging and drug delivery. In this study, an MXene material, Ti₃C₂T_x, was developed to play dual functional roles in wastewater treatment and electrochemical energy storage. First, Ti₃C₂T_x MXene demonstrated its high capacity for the adsorption of selected cationic dyes such as Rhodamine B in aqueous solutions. Meanwhile, both XPS and Raman spectroscopy indicated that Ti₃C₂T_x hosted the organic dyes in its interlayer voids through intercalation. After the in situ carbonization, conversion of the organic dyes to carbon led to the formation of novel carbon-filled Ti₃C₂T_x (Ti₃C₂T_x/C) for electrochemical applications. With the increased interlayer thickness of carbon within Ti₃C₂T_x/C, the carbon-filled Ti₃C₂T_x hetero-structure was eventually applied as a supercapacitor electrode; it displayed a high specific capacity of 226 F g⁻¹ at 1 A g⁻¹. Our unique approach of cationic dye adsorption/carbonization significantly enhanced the transport paths of electrolyte ions into the MXene, i.e. it exhibited high performance and cycling stability, with 94% retention over 8000 cycles. Our study paves the way to achieve scalable and environmental friendly processes for the development of high-performance 2D nanomaterials for energy storage.