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.