Environmentally friendly Y2MoO6 high near-infrared reflective yellow pigment based on Bi doping

Herein, a series of environmentally friendly rare earth doped yellow pigments with near-infrared (NIR) properties were synthesized using solid-state reaction at a high temperature of 1200 °C, with the general formula Y 2−x Bi x MoO 6 . The prepared pigments were characterized using analytical techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), CIE 1976 color space system, ultraviolet–visible/near infrared (UV–Vis/NIR) spectroscopy. Results indicated that its color changes from white to yellow after doping with Bi 2 O 3 in Y 2 MoO 6 . As the doping amount of Bi increased, the yellow color gradually deepened. All the doped samples exhibited a monoclinic structure with space group C 2/ c (15). When the optimal doping ratio was Y 1.8 Bi 0.2 MoO 6 (i.e., x = 0.2), the NIR reflectance (R%) and NIR solar reflectance (R∗%) of the pigment sample both exceeded 100 %. In the study of acid and alkali resistance, the color difference value ΔE∗ before and after pigment soaking was less than 5, indicating good chemical stability. In the coating study, the temperature difference between the air inside the pigment-coated house model and the air inside the uncoated house model reached 7 °C after 20 min of irradiation using an infrared lamp, suggesting that the prepared pigment reflects solar thermal radiation well and demonstrates good thermal insulation performance.