Synthesis and Characterization of Yellow Pigments of Bi1.7RE0.3W0.7Mo0.3O6 (RE = Y, Yb, Gd, Lu) with High NIR Reflectance

Brilliant yellow-orange pigments based on the formula Bi1.7RE0.3W0.7Mo0.3O6 (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 Bi2WO6 results in the colors of pigments varying from faint yellow to brilliant yellow orange. Compared with Bi2WO6 pigment, the typical pigment of Bi1.7Lu0.3W0.7Mo0.3O6 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 Bi1.7Lu0.3W0.7Mo0.3O6 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.