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Title:
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Structural and Visible-Near Infrared Optical Properties of Cr-Doped TiO 2 for Colored Cool Pigments.
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Authors:
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Yuan L; National Engineering Research Center of Electromagnetic Radiation Control Materials, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.; Key Laboratory of Fluid and Power Machinery of Ministry of Education, Center for Advanced Materials and Energy, Xihua University, Chengdu, 610039, People's Republic of China.
Weng X; National Engineering Research Center of Electromagnetic Radiation Control Materials, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China. .
Zhou M; Key Laboratory of Fluid and Power Machinery of Ministry of Education, Center for Advanced Materials and Energy, Xihua University, Chengdu, 610039, People's Republic of China.
Zhang Q; Key Laboratory of Fluid and Power Machinery of Ministry of Education, Center for Advanced Materials and Energy, Xihua University, Chengdu, 610039, People's Republic of China.
Deng L; National Engineering Research Center of Electromagnetic Radiation Control Materials, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.
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Source:
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Nanoscale research letters [Nanoscale Res Lett] 2017 Nov 17; Vol. 12 (1), pp. 597. Date of Electronic Publication: 2017 Nov 17.
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Publication Type:
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Journal Article
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Language:
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English
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Imprint Name(s):
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Original Publication: New York, NY : Springer
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Grant Information:
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51402241 National Natural Science Foundation of China; 15ZB0138 Research Project of the Education Department of Sichuan Province; SZJJ2017-063 Open Research Subject of Key Laboratory of Special Materials and Manufacturing Technology
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Contributed Indexing:
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Keywords: Color; Cool pigment; Cr-doping; Reflection spectrum; Titanium dioxide
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Entry Date(s):
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Date Created: 20171118 Latest Revision: 20200929
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Update Code:
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20240105
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PubMed Central ID:
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PMC5691828
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DOI:
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10.1186/s11671-017-2365-5
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PMID:
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29149423
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Chromium-doped TiO 2 pigments were synthesized via a solid-state reaction method and studied with X-ray diffraction, SEM, XPS, and UV-VIS-NIR reflectance spectroscopy. The incorporation of Cr 3+ accelerates the transition from the anatase phase to the rutile phase and compresses the crystal lattice. Moreover, the particle morphology, energy gap, and reflectance spectrum of Cr-doped TiO 2 pigments is affected by the crystal structure and doping concentration. For the rutile samples, some of the Cr 3+ ions are oxidized to Cr 4+ after sintering at a high temperature, which leads to a strong near-infrared absorption band due to the 3 A 2 → 3 T 1 electric dipole-allowed transitions of Cr 4+ . And the decrease of the band gap causes an obvious redshift of the optical absorption edges as the doping concentration increases. Thus, the VIS and near-infrared average reflectance of the rutile Ti 1 - x Cr x O 2 sample decrease by 60.2 and 58%, respectively, when the Cr content increases to x = 0.0375. Meanwhile, the color changes to black brown. However, for the anatase Ti 1 - x Cr x O 2 pigments, only the VIS reflection spectrum is inhibited by forming some characteristic visible light absorption peaks of Cr 3+ . The morphology, band gap, and NIR reflectance are not significantly affected. Finally, a Cr-doped anatase TiO 2 pigment with a brownish-yellow color and 90% near-infrared reflectance can be obtained.