Abstract
MXenes are a class of two-dimensional (2D) materials composed of transition metal carbides, nitrides, and carbonitrides. Due to their high electrical conductivity, hydrophilicity, and tunable surface chemistry, they have gained significant attention. These materials are typically synthesized from layered ternary precursors known as MAX phases, with the general formula Mn+1AXn, where M is an early transition metal, A is a group 13 or 14 element, and X is carbon and/or nitrogen. The transformation from MAX to MXene occurs via selective etching of the A-layer. Choosing an appropriate synthesis and etching strategy plays a critical role in determining the structural and functional properties of the resulting MXene. This review provides a comprehensive analysis of recent advances in the synthesis of MAX phases and the production of MXene materials. Particular focus is placed on etching methods ─ such as hydrofluoric acid (HF), in situ HF (LiF + HCl), molten salts, and electrochemical techniques ─ and their effects on MXene morphology, surface terminations, and functional properties. Comparative analysis reveals that each method has distinct advantages and limitations in terms of safety, scalability, and product quality. The review also highlights current challenges, including the need for fluorine-free and environmentally safe etching processes and the importance of controlling surface terminations. Finally, future directions are proposed for adapting MXene synthesis routes for use in next-generation energy storage systems, catalysis, environmental remediation, and electronics.