中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 25 No. 8 August 2015 |
（1. National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,
Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
2. Key Laboratory of Green Process and Engineering,
Chinese Academy of Sciences, Beijing 100190, China;
3. University of Chinese Academy of Sciences, Beijing 100049, China;
4. Shandong Provincial Academy of Building Research, Jinan 250031, China;
5. College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109, China）
Abstract:In order to reduce greenhouse gas emission and urban heat island mitigation, pure and titanium(Ti)-doped Cr2O3 cool pigments were prepared via the thermal decomposition of CrOOH. The result reveals that the pure Cr2O3 pigment presents both a high near-infrared reflectance and excellent yellowish-green color. Meanwhile, titanium was doped to improve the NIR reflectance and strengthen the color. The color of the designed pigments was brighter, and most importantly, the NIR reflectance increased from 84.04% to 91.25% with increasing Ti content from 0 to 0.006% (mole fraction). However, excessive doping of Ti4+ for Cr3+ in Cr2O3 (x(Ti)≥0.008%) decreased the NIR reflectance. One possible reason is that the conductivity type of the Cr2-xTixO3+δ changed from p-type conduction to n-type conduction with increasing Ti content, accompanied by the change of the electrical resistivity and the NIR reflectance. The prepared yellowish-green Cr2O3 pigments have a great potential for extensive applications in construction and military.
Key words: CrOOH; cool pigments; NIR reflectance; Ti-doped Cr2O3
