Safe Etching Route of Nb₂SnC for the Synthesis of Two-Dimensional Nb₂CT_x MXene: An Electrode Material with Improved Electrochemical Performance

In this study, low-temperature synthesis of a Nb₂SnC non-MAX phase was carried out via solid-state reaction, and a novel approach was introduced to synthesize 2D Nb₂CT_x MXenes through selective etching of Sn from Nb₂SnC using mild phosphoric acid. Our work provides valuable insights into the field of 2D MXenes and their potential for energy storage applications. Various techniques, including XRD, SEM, TEM, EDS, and XPS, were used to characterize the samples and determine their crystal structures and chemical compositions. SEM images revealed a two-dimensional layered structure of Nb₂CT_x, which is consistent with the expected morphology of MXenes. The synthesized Nb₂CT_x showed a high specific capacitance of 502.97 Fg^-1 at 1 Ag^-1, demonstrating its potential for high-performance energy storage applications. The approach used in this study is low-cost and could lead to the development of new energy storage materials. Our study contributes to the field by introducing a unique method to synthesize 2D Nb₂CT_x MXenes and highlights its potential for practical applications.