A new green thermal insulating ceramic pigment with high near-infrared reflectance: Mn2+ doped BaAl2O4

In this paper, a series of Ba1-xMnxAl2O4 (x = 0.00 0.02 0.05 0.10 0.15 0.20) green high NIR reflective pigments were prepared by solution gel method and applied to ceramic glaze for thermal insulation evaluation. The experimental results show that Mn2+ ions successfully replace Ba2+ ions without changing the morphology of the phase structure of the materials. The Ba1-xMnxAl2O4 morphology shows nanowire-like shape as detected by SEM. The absorption of Mn2+ ions in the visible region changes the color of the materials from white to green, and with the a* values in the range of −20.28 to −58.17, the materials have excellent coloring properties. The near-infrared reflectivity of the material in the range of 700–2500 nm is 47.35%–68.07%, which is significantly higher than other materials of the same color. In the heat insulation application experiment, the inner surface temperature of ceramic glazes with Ba1-xMnxAl2O4 materials was reduced by 16.17%–23.87% compared to ordinary ceramic samples.