Unveiling the potential of M2X MXenes: Structure, properties, synthesis strategies, and supercapacitor applications

2D MXenes have received significant attention due to their remarkable properties, including superior electrical conductivity, chemical stability, tunable surface chemistry, structural flexibility, and excellent thermal and magnetic characteristics, making them highly suitable for supercapacitors. Since their discovery in 2011, M₃X₂ MXenes have been widely studied, while M₂X MXenes, despite their equally impressive properties, have been comparatively less explored. M₂X MXenes offer promising potential for a wide range of applications, particularly in energy storage systems like supercapacitors. This review provides a comprehensive overview of the current energy storage crisis and the increasing demand for advanced materials. It introduces the fundamentals of MXenes, with a detailed focus on M₂X MXenes, and explains their structure, properties, and various synthesis methods. The review also highlights the application of M₂X MXenes in supercapacitors and also provided a detailed discussion of their advantages and challenges. In conclusion, the article outlines the key challenges and future directions in the field, aiming to serve as a valuable guide for MXene research and supercapacitor development.