Perspectives for Infrared Properties and Applications of MXene

MXene is a large family of two-dimensional transition metal carbides, nitrides or carbonitrides.Its characteristics (various compositions, two-dimensional atomic layer structures, metallic electrical conduction, active surfaces, etc.) render MXene unique interactions with electromagnetic waves at different frequencies (visible light, infrared, terahertz, microwave, etc.), deriving a variety of electromagnetic functional applications.In the infrared range, MXene has a wide range of infrared radiation properties, and its active surface enables tunable infrared absorption.These features have attracted researchers' interest in exploring infrared properties of MXene and the corresponding applications in recent years.In this perspective, the intrinsic infrared characteristics and manipulation strategies of different MXenes are systematically summarized, and the research progress of representative infrared applications are briefly introduced, including infrared identification/camouflage, surface plasmon, photothermal conversion, and infrared photodetection.Particularly, the contribution and mechanism of MXene in these applications are discussed.Finally, the outlook of infrared functional applications with MXenes are proposed.