Intercalation-driven tunability in two-dimensional layered materials: Synthesis, properties, and applications

Two-dimensional (2D) layered materials have attracted considerable research attention due to their unique and tunable properties. Intercalation, the insertion of ions, atoms, or molecules into the interlayer spaces of these materials, facilitates the reversible modulation of both the intercalated species and the host structure without compromising the strong in-plane covalent bonds. This technique significantly enhances the material's composition, structure, and physical, chemical, and electronic properties, thus creating a highly adaptable system with potential applications in electronics, optics, and catalysis. This review comprehensively details various synthesis methodologies, including conventional electrochemical techniques, liquid-phase, and vapor-phase intercalation, alongside specialized methods such as ion exchange and self-intercalation. We further elucidate the emergent properties resulting from intercalation and highlight recent advancements in their applications within electronics, optoelectronics, magnetoelectronics, and catalysis. Finally, the burgeoning opportunities and formidable challenges associated with the development of intercalated 2D materials are discussed.