Combined Experimental and DFT Study on 2D MoSe2 toward Low Infrared Emissivity
Low infrared emissivity materials play a key role in thermal camouflage or retardation. Among these, fillers can be easily shaped into various flexible forms and normally provide an omnidirectional and polarization-insensitive emissivity. However, conventional fillers suffer from drawbacks of full-waveband ultrahigh reflectivity, unsatisfactory thermal camouflage performances, or poor chemical/thermal stabilities. Herein, 2D MoSe 2 is discovered as a new semiconductor with intrinsic low infrared emissivity after first-principle density functional theory calculation and experimental demonstration on eight types of two-dimensional materials (2DMs). Mechanisms of electron–photon reflection and phonon–photon absorption for the low infrared emissivity are proposed. A two-step microwave-assisted amination process is developed to exfoliate the nanosheets and obtain a desired low infrared emissivity. The as-obtained chitosan modified MoSe 2 (CS@MoSe 2 ) has an ultrahigh spectral reflectivity of 78%–86% in 8–14 µm, and its resin-based coating still exhibits a low infrared emissivity of 0.32 and shows a dramatic reduction in radiation temperature of 28 °C for a hot object at 70 °C. Besides, CS@MoSe 2 can endure a high temperature of 220 °C and is demonstrated with a long-term thermal camouflage efficiency in hot environments. This work will guide 2DMs selection and preparation toward desired infrared radiation properties to satisfy numerous applications.
危险品化学品经营许可证（带存储）