Recent Advances in Functional 2D MXene-Based Nanostructures for Next-Generation Devices

Similar to graphene and black phosphorus (BP), 2D transition metal carbides and nitrides (MXenes) are of great interest in a variety of fields, such as energy storage and conversion, sensors, electromagnetic interference (EMI) shielding, and photothermal therapy due to their excellent conductivity and hydrophilicity, large specific capacitance, high photothermal effect, and superior electrochemical performance. To further broaden applicable ranges beyond their existing boundaries and fully exploit these potentials, functional 2D MXene nanostructures in recent years have been rationally designed and developed by various approaches, such as doping strategies, surface functionalization, and hybridization, for next-generation devices with the merits of low power consumption, intelligence, and high-integration chips. This review provides an overview of the synthetic routes and fundamental properties of functional 2D MXene nanostructures, including surface-modified 2D MXenes and mixed-dimensional MXene-based heterostructures, highlights the state-of-the-art progress in the applications of functional 2D MXene nanostructures with regard to energy storage and conversion, catalysis, sensors, photodetectors, EMI shielding, degradation, and biomedical applications, and presents the challenges and perspectives in these burgeoning fields. It is hoped that this review will inspire more efforts toward fundamental research on new functional 2D MXene-based devices to satisfy the growing requirements for next-generation systems.