Synthesisof Novel NontoxicYellow Pigments: Sr2Ce1¹xTbxO4

Abstract

Novel yellow inorganicpigments Sr2Ce1¹xTbxO4 (x=0, 0.2, 0.4, 0.6, 0.8, and 1.0) were synthesized by the conventional solid-state route. The structure and morphology ofthe developed pigments were characterized using powder X-ray diffractometer (XRD) and scanning electron microscope (SEM), respectively. AUV­vis­NIR spectrophotometer was employed toinvestigate the optical properties, and the color characteristics were evaluated by CIE 1976L*a*b*color scales. The Tb substitution extends the absorption edge tolonger wavelengths by introducing an additional electroniclevel between the valence and conduction bands. Consequently, the prepared pigments exhibit various yellow colors byfine tuning ofthe band gap from 3.03 (white) to 2.52 eV (reddish-greenish yellow). Doping ofTbinto Sr2CeO4enhances the NIR reflectance at 1100 nmfrom 87%to 91%. The coloring performance of the synthesized pigments wasinvestigated in the polymer matrix for plasticcoloring applications. The exhibition of high NIR reflectance with comparablecolor properties of these pigments makes them potentialcandidates as coolcolorants to reduce the heat build-up