Synthesis, Structural Characterization, and Electrochemical Performance of Delaminated Mo ₂ CT _<i>x</i> MXenes for Applications as Supercapacitors

Research on two-dimensional (2D) MXenes continues to gain substantial momentum owing to their compositional tunability and broad technological relevance. MXene-based electrodes are promising candidates for energy storage applications in renewable energy systems, contributing to energy-efficient, low-carbon technologies. In the present study, a Mo2Ga2C MAX precursor is synthesized using molybdenum carbide (MoC) powder and gallium ingot in a 1:1 molar ratio at 850 °C, followed by controlled etching to obtain a delaminated few-layer molybdenum carbide MXene (d-Mo2CTx). Comprehensive physicochemical characterizations are performed using XRD, XPS, Raman spectroscopy, HRSEM, EDS, E-mapping, FTIR spectroscopy, and UV–visible spectroscopy. XRD confirms the successful conversion of Mo2Ga2C to Mo2CTx, evidenced by the shift of the (002) reflection and the emergence of the (006) peak, signifying interlayer expansion and gallium removal. XPS analysis confirmed the successful formation of the Mo2CTx MXene with characteristic Mo–C bonding and surface terminations (–O and −OH). HRSEM reveals the morphological evolution from the dense MAX phase to few-layered 2D nanosheets, while EDS and elemental mapping confirmed Ga elimination and the homogeneous distribution of Mo, C, O, F, and Cl. Raman, FTIR, and UV–vis analyses further substantiated the structural reorganization and surface functionalization. Electrochemical evaluation through cyclic voltammetry, chronopotentiometry, and impedance spectroscopy demonstrated electric double-layer capacitive behavior with a specific capacitance of 11.9 F g–1 at a scan rate of 5 mV/s and 11.1 F g–1 at an applied current of 0.01 mA, a rapid response (21 ms), a low equivalent series resistance (21.2 Ω), and an 82.7% capacitance retention after 5000 cycles, underscoring the potential of Mo2CTx MXene for high-performance supercapacitor applications and clean energy technology.