Bismuth and Vanadium-Substituted Yttrium Phosphates for Cool Coating Applications.
Vasudevan Elakkiya1, Shanmugam Sumathi1
1Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore632014, India.
ACS Omega
|December 12, 2022
Summary
Engineered yttrium phosphate with bismuth and vanadium creates a novel yellow pigment. This environmentally benign pigment exhibits enhanced near-infrared reflectance and stability, making it suitable for cool coatings.
Area of Science:
- Materials Science
- Inorganic Chemistry
- Nanotechnology
Background:
- Yttrium phosphate (YPO4) serves as a host lattice for pigment development.
- Traditional yellow pigments often lack environmental benignity or desired optical properties.
- Near-infrared (NIR) reflective pigments are crucial for cool material applications.
Purpose of the Study:
- To engineer an environmentally benign yellow pigment with high NIR reflectance.
- To investigate the effect of bismuth (Bi) and vanadium (V) co-substitution in YPO4.
- To evaluate the optical properties, morphology, and stability of the synthesized materials.
Main Methods:
- Precipitation method used to synthesize YPO4 doped with Bi and V.
- Series of compositions: YP(1-x)VxO4, Y(1-y)BiyPO4, and Y(1-y)BiyP(1-x)VxO4.
- Characterization techniques included X-ray Photoelectron Spectroscopy (XPS) and optical measurements.
Main Results:
- Co-substitution of Bi and V in YPO4 enhanced yellow color and NIR reflectance.
- The optimized pigment Y0.4Bi0.6P0.4V0.6O4 achieved 83% NIR reflectance, up from 68% for pure YPO4.
- XPS confirmed the presence of trivalent Bi and pentavalent V.
- Enhanced morphology led to increased scattering coefficient and NIR reflectance.
Conclusions:
- Y0.4Bi0.6P0.4V0.6O4 is a promising environmentally benign cool yellow pigment.
- The pigment demonstrates excellent yellow hue (b* = +56.06) and high NIR solar reflectance (R* = 83%).
- Good chemical and thermal stability ensures its suitability for practical applications.
