Etching duration as a key parameter for tailoring Ti3C2Tx MXene electrochemical properties

Abstract

Since the groundbreaking discovery of 2D MXenes in 2011, these materials have garnered immense interest for their exceptional properties in energy storage applications. The performance of MXenes in this domain is highly dependent on synthesis parameters, with the synthesis kinetics playing a pivotal role. In this work, Ti₃C₂T_x MXene was produced through hydrofluoric (HF) acid etching, conducted over durations of 48, 72, and 96 h. The resulting MXene was comprehensively characterized to examine its structural and morphological attributes. It was observed that the interlayer spacing of Ti₃C₂T_x MXene was influenced by the etching time, led to the formation of defects in the material's layers. Among the samples, the one obtained by etching for 72 h exhibited the optimal specific capacitance, achieving 488 Fg^-1 at a current density of 0.25 Ag^-1, along with excellent rate performance. A supercapacitor device assembled using this MXene and activated carbon delivered an energy density of 5 Whkg⁻¹ and a power density of 1000 Wkg^-1, accompanied by outstanding cyclic stability. These findings underscore the critical importance of etching duration in enhancing the electrochemical performance of MXene materials.