Simple synthesis of rice grain‐like BiVO ₄ powders as yellow and near‐infrared reflective pigment for heat‐ and sun‐resistant paint

Abstract This study synthesized bismuth orthovanadate (BiVO 4 ) powders as yellow and near‐infrared reflective pigments using a modified ethylene glycol‐assisted colloidal method at various calcination temperatures. The pigment samples were characterized using X‐ray diffraction, scanning electron microscopy, UV–visible absorption spectroscopy, near‐infrared reflection spectroscopy, and energy‐dispersive X‐ray spectroscopy. Additionally, the color of the samples was evaluated using the CIE L*a*b* color space, and their photocatalytic activity was assessed via the degradation of methylene blue. The results revealed that both the solvent used during crystallization and the calcination temperature are critical factors influencing the crystal structure and particle morphology, which in turn determine the optical properties of the pigment samples. Notably, when ethylene glycol was used as the solvent and the calcination temperature was set at 400 °C, the resulting pigment primarily consisted of the ms –BiVO 4 phase with rice grain‐like morphology and particle sizes ranging from 1.3 to 5 µm. This sample exhibited an enhanced yellow color, along with excellent near‐infrared reflectivity and strong UV absorption, but minimal photocatalytic activity. These characteristics make it highly suitable for use as a pigment in heat‐ and sun‐resistant paints.