<p>Recent advancements in two-dimensional (2D) materials have focused on MXenes as candidate materials for future energy storage and water splitting devices owing to their outstanding electrical conductivity, hydrophilicity, tunable surface chemistry, large specific surface area, and excellent electrochemical activity. This review is devoted to summarizing a comprehensive overview of the latest developments in MXene-based materials for high-performance supercapacitors and electrocatalytic water splitting. The synthesis strategy, structural characteristics, surface functionalization approaches, and the composite formation technique are critically discussed to establish the influence of the electrochemical performance. Particular emphasis is placed on the role of MXene in promoting charge transfer, accelerating the ion diffusion, and enhancing electrochemical kinetics, leading to superior capacitance, rate capability, cyclic stability, and highly efficient HER, OER, and overall water splitting performance. This review also critically examines the major challenges limiting practical implementation, including oxidation instability, nanosheet restacking, limited large-scale synthesis, and long-term durability. Finally, the future research perspectives are proposed, focusing on scalable synthesis and surface interface engineering, defect and heterostructure engineering, and device integration to accelerate the development of efficient, stable, commercially viable MXene-based materials for sustainable energy storage and hydrogen production. By systematically correlating material design with electrochemical performance, this review provides valuable insight and practical guidelines for the rational development of advanced MXene-based energy storage and water splitting systems.</p> Graphical abstract <p></p>