Effect of voids on the performance of MXene-based nanocomposites
Two-dimensional transition metal carbides/nitrides (MXenes) exhibit exceptional mechanical and electrical properties, positioning them as promising candidates for electronics, aerospace, and energy storage. However, assembling MXene nanosheets into high-performance macroscopic nanocomposites remains challenging due to low stress-transfer efficiency between nanosheets. This review systematically examines the role of voids within MXene-based nanocomposites, revealing that voids can paradoxically enhance performance under specific conditions. We discuss strategies to mitigate detrimental voids, including synergistic interfacial interactions, nanosheet filling, fabrication process optimization, and nanoconfined assembly. Empirical data from referenced studies indicate that void content critically influences mechanical reinforcement; for instance, graphene oxide monolayers exhibit a Young's modulus of approximately 200 GPa, while MXene monolayers reach 330 GPa. The review also highlights that controlled nanovoid dispersion in metals can increase strength by up to 50% without sacrificing ductility. We provide a roadmap for fabricating high-performance MXene-based nanocomposites, emphasizing the need to balance void elimination with intentional void engineering. This work consolidates current understanding and identifies pathways to overcome the stress-transfer bottleneck, enabling scalable production of MXene composites with tailored properties for demanding applications.