Pigments based on terbium-doped yttrium cerate with high NIR reflectance for cool roof and surface coating applications

• New red pigments, Y2Ce2−xTbxO7 were synthesized by a conventional solid state route.
• The pigments exhibit various red colors by tuning the band gap from 3.11 to 1.87 eV.
• They show intense redness value around 26 with enhanced NIR reflectance (80%).
• The coloring performance was demonstrated in PMMA, roofing materials and tiles.
• They demonstrate as potential NIR reflective red colorants for cool roofs.

A new class of pigments: Y2Ce2−xTbxO7 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were synthesized by a conventional solid state route. The Tb substitution extends the absorption edge to longer wavelengths by introducing an additional electronic level between the valence band and conduction band leading to various red colors by fine tuning the band gap from 3.11 eV (ivory white) to 1.87 eV (red). The pigments displayed intense red color (a* = 26) with high near infrared reflectance (80%). The applicability studies of these pigments in polymer matrix (poly methyl methacrylate), cement slab, asbestos sheet and ceramic glazes exhibited good coloring performance with high near infrared reflectance. These results demonstrate the synthesized pigments as potential near infrared reflective candidates for cool roof and surface coating applications.