VO2/ZnS core-shell nanoparticle for the adaptive infrared camouflage application with modified color and enhanced oxidation resistance

VO2 has attracted extensive attention as an adaptive camouflage material due to its structural change during the metal-insulator transition (MIT) at 68 degrees C, which can fast respond to ambient temperature and actively modulate infrared emissivity. However, the thermal instability and undesirable color have restricted its applications in multi-spectral camouflage. In this study, the VO2/ZnS core-shell nanoparticles were synthesized via a homogeneous precipitation method. The VO2 nanoparticle core exhibited a remarkable infrared emissivity modulation ability in the mid-wavelength and long-wavelength thermal atmospheric windows. The ZnS shell, as an infrared transparent material, not only modified the color of VO2 nanoparticle from unpleasant blue-black to gray-green that adapts to visible camouflage in the woodland background, but also significantly enhanced the oxidation resistance. This is the first report of such a single nanoparticle structure with both variable infrared emissivity and desirable color that offer significant potential for multi-spectral camouflage application.