Abstract:

The urban island effect and energy crisis can be relieved usefully by environmentally benign and high near-infrared reflective pigments, which is of great significance to develop of green energy-saving industry. Ions doping is an effective way to achieve the color diversity of high near infrared reflective pigments. In this work, a series of high near-infrared reflection Ba_1-xCu_xZr_1-yTb_yO₃ (x=0.15, 0.25, 0.35; y=0, 0.15) inorganic pigment co-doped with Cu ²⁺and rare earth Tb ³⁺was prepared by a Sol-Gel process. Its phase structure, ultraviolet/visible/near-infrared reflectance, and color parameters of the synthesized pigment samples were investigated and characterized by X-ray diffraction (XRD), UV/Vis/NIR spectroscopy, and color CIE-L ^*a ^*b ^* 1976 color scales. The results demonstrate that all synthesized pigments have cubic perovskite structure after calcined at 1100 ℃. The co-doping of Cu ²⁺ and Tb ³⁺ is successfully introduced into the BaZrO₃ lattice, and the color increasingly changes from white to gray, and to yellow with the increase of Cu ²⁺and Tb ³⁺concentration. Meanwhile, the obtained pigments possess high near-infrared solar reflectance in the range of 780-2500 nm, the average reflectance is up to 80%. Therefore, these Ba_1-xCu_xZr_1-yTb_yO₃ cool powdered pigment have great application prospect in the building coatings.

Key words: Sol-Gel, co-doping, near-infrared reflectance, cool pigment