In situ construction of pomegranate-like γ-[Li]-Ce2S3@ c-SiO2 as high-temperature and acid tolerant red pigment

• DOI: 10.1016/j.apsusc.2021.149643
• Publication Date: 2021-03-27T07:43:54Z
• Authors: Fusheng Song; Yueming Li; Yongzhi Yu; Zongyang Shen; Zhumei Wang
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract Development of non-toxic, high-temperature and acid tolerant red pigment is of significance for ceramic decoration. Here, we report a microemulsion and controlled calcination route to prepare pomegranate-like microscale particles consisting of inlaid Li-doped γ-Ce2S3 red pigment in cristobalite (c-SiO2) subunits (pomegranate-like γ-[Li]-Ce2S3@c-SiO2) with greatly improved high-temperature stability and acid corrosion resistance. The key of this method is to synthesize the precursors of γ-[Li]-Ce2S3@c-SiO2 during microemulsion process, which is particularly sensitive to synthesis conditions. The optimum parameters in terms of orthogonal experiment are the Ce/Si mole ratio of 1:9, 45 °C of reaction temperature, and 4.5 ml of ammonia (25.0 wt%). When the precursor above is treated by sulfurization and calcination, the obtained pomegranate-like γ-[Li]-Ce2S3@c-SiO2 exhibits outstanding properties. After soaking in concentrated hydrochloric acid (12.0 mol/L) for 24 h followed by calcining at 900 °C in air, the pomegranate-like γ-[Li]-Ce2S3@c-SiO2 still shows a bright red color. These excellent performances are primarily attributed to the outer dense c-SiO2 coating, which plays a key role in successfully preventing the inner γ-[Li]-Ce2S3 from acid and thermal corrosion. The high-temperature stability and anti-acid corrosion highlight the promise of its potential for commercial red ceramic pigments.