Synthesis and Characterization of Yellow Pigments of Bi 1.7 RE 0.3 W 0.7 Mo 0.3 O 6 (RE = Y, Yb, Gd, Lu) with High NIR Reflectance

Brilliant yellow-orange pigments based on the formula Bi 1.7 RE 0.3 W 0.7 Mo 0.3 O 6 (RE = Y, Yb, Gd, Lu) are developed by the traditional solid-state reaction method. Relevant techniques are used for characterization of the crystal structure, morphology feature, reflectance property, and color performance of the prepared pigment. The doping of RE/Mo in Bi 2 WO 6 results in the colors of pigments varying from faint yellow to brilliant yellow-orange. Compared with Bi 2 WO 6 pigment, the typical pigment of Bi 1.7 Lu 0.3 W 0.7 Mo 0.3 O 6 greatly improves the yellow hue component ( b *) value to be 72.03. Moreover, the NIR reflectances of all of the samples are higher than 95%, and their NIR solar reflectances are above 94%. The typical pigment of Bi 1.7 Lu 0.3 W 0.7 Mo 0.3 O 6 coated on galvanized sheet exhibits excellent coloring performance with a high NIR solar reflectance (83.32%). The acid/alkali resistance studies reveal that the pigments are chemically stable under the atrocious weather conditions. Thus, the superior performances of synthesized pigments have exhibited potential for energy savings.