Synthesis and Optical Properties Based on Ni-Doped Zn<sub>2</sub>SiO<sub>4</sub> Blue Pigments with High-NIR Reflectance
Qiuying Wang, Zhiwei Wang, Menghang Qi, Hang Zhao, Xin Xin, Anjali Verma, Theeranun Siritanon, A. P. Ramirez, M. A. Subramanian, Peng Jiang
Abstract
The severe urban heat island effect emphasizes the heightened importance of reducing building energy consumption. Cool pigments with higher near-infrared reflectivity contribute to the overall coating performance of the building. In this work, a novel intense blue pigment with superior infrared reflectance based on Ni-doped Zn 2 SiO 4 was successfully synthesized via the simple solid-state method. The crystal structure, oxidation states, and optical properties are analyzed. The oxidation state of Ni was confirmed to be +2 using magnetic analysis and XPS. The intense blue color exhibited by the solid solution is due to the 3 T 1 ( 3 F) → 3 T 1 ( 3 P) transition of Ni 2+ at the tetrahedral sites. UV–vis–NIR spectra demonstrate that this pigment exhibits superior near-infrared reflectance compared to cobalt blue in the range of 900–1700 nm, indicating its potential application in the realm of building energy conservation.