Preparation and properties of Ba~(2+)-Y~(3+) co-doped γ-Ce2S3 red pigment

摘要

In this study, Ba~(2+)-Y~(3+) co-doped y-Ce2S3 (abbreviated as γ-[Ba,Y]-Ce2S3) red pigments were synthesized by a co-precipitation method according to the composition of n(Ba)/n(Ce_(1-x)Y_x = 0.1 (molar ratio, x = 0, 0.01, 0.03, 0.05, and 0.10 mol). The corresponding vulcanized products, (/-[Ba,Y]-Ce2S3 red pigment (SYX), were prepared at 850°C for 150 min by using CS2 as a sulphur source. The effect of the Y~(3+)doping content on the phase composition, chroma-ticity, and thermal stability of Ba~(2+)-Y~(3+) co-doped y-Ce2S3 was systematically investigated by FE-SEM, EDS, XRD, Raman spectroscopy, HR-TEM, XPS, CIELAB colorimeter, and TG-DTA. The results show that a pure y phase can be obtained for SY_x at 850°C, whenx is varied from Oto 0.05 mol. Whereas new heterogeneous phases, i.e., a-Ce2S3 and BaY2S4, were observed when the Y~(3+) content was larger than 0.05. As the Y~(3+) content increased, the band gap of y-[Ba,Y]-Ce2S3 increased from 2.12 eV to 2.15 eV, which led to a colour change from red to red-orange. The chromaticity value of the pigments was raised from L* = 31.84, a* = 30.95, b* = 23.63 (S.Y_(0.00)) to L* = 36.69, o* = 41.83, b* = 41.00 (S.Y_(0.01)), indicating that the Ba~(2+)-Y~(3+) co-doping can effectively increase the chromaticity value. The S.Y_(0.01) sample still presented a pure (/-phase after heat treatment at 440 °C for 10 min in air, which indicated that the Ba~(2+)-Y~(3+) co-doping successfully increased the thermal stability of the γ-[Ba;Y]-Ce2S3 red pigment.