Advances in Titanium Carbide (Ti 3 C 2 T x ) MXenes and Their Metal-Organic Framework (MOF)-Based Nanotextures for Solar Energy Applications: A Review.

Introducing new materials with low cost and superior solar harvesting efficiency requires urgent attention to solve energy and environmental challenges. Titanium carbide (Ti 3 C 2 T x ) MXene, a 2D layered material, is a promising solution to solve the issues of existing materials due to their promising conductivity with low cost to function as a cocatalyst/support. On the other hand, metal-organic frameworks (MOFs) are emerging materials due to their high surface area and semiconducting characteristics. Therefore, coupling them would be promising to form composites with higher solar harvesting efficiency. Thus, the main objective of this work to disclose recent development in Ti 3 C 2 T x -based MOF nanocomposites for energy conversion applications to produce renewable fuels. MOFs can generate photoinduced electron/hole pairs, followed by transfer of electrons to MXenes through Schottky junctions for photoredox reactions. Currently, the principles, fundamentals, and mechanism of photocatalytic systems with construction of Schottky junctions are critically discussed. Then the basics of MOFs are discussed thoroughly in terms of their physical properties, morphologies, optical properties, and derivatives. The synthesis of Ti 3 C 2 T x MXenes and their composites with the formation of surface functionals is systematically illustrated. Next, critical discussions are conducted on design considerations and strategies to engineer the morphology of Ti 3 C 2 T x MXenes and MOFs. The interfacial/heterojunction modification strategies of Ti 3 C 2 T x MXenes and MOFs are then deeply discussed to understand the roles of both materials. Following that, the applications of MXene-mediated MOF nanotextures in view of CO 2 reduction and water splitting for solar fuel production are critically analyzed. Finally, the challenges and a perspective toward the future research of MXene-based MOF composites are disclosed.