MXene/biomacromolecule composites: structures, properties, fabrication and applications

MXene/biomacromolecule composites have rapidly emerged as a versatile class of hybrids that couple the electrical and photothermal functionalities of MXenes with the mechanical reinforcement and bio-derived processability of natural macromolecules. This review establishes a unified framework for the field by classifying the architectures reported into four representative categories, namely membranes or films, papers, gels, and nonwoven structures, and by systematically comparing their fabrication strategies, including vacuum-assisted assembly, solution casting, printing, electrospinning, and gelation. The interfacial assembly principles governing structure formation and property retention are summarized, with an emphasis on interfacial hydrogen bonding, electrostatic and coordination interactions, together with hierarchical structural confinement that suppresses MXene restacking and enables continuous transport pathways. Recent progress is critically compared across electromagnetic interference shielding, soft actuation, biomedicine, energy storage, flexible electronic devices, and water purification, highlighting structures, properties, application correlations and performance-limiting factors. Key challenges and opportunities are identified, including oxidation mitigation and long-term stability, scalable manufacturing and large-area processing, standardized biosafety evaluation, and multifunctional integration guided by computations and machine learning. This review provides design principles and practical considerations to accelerate the rational development of robust and sustainable MXene/biomacromolecule composites.