Multifunctional ternary entropy-regulatory RE2W2O9 (RE = Ce, Gd, Ho) yellow pigments: high near-infrared reflectance, anti-ultraviolet aging, and antimycotic performance

To mitigate the urban heat island effect, align with the “double carbon strategy”, and address the issues of coating aging and mildew on building facades, multifunctional ternary entropy-regulatory tungstate ceramic cool pigments (Ce x Ho 0.1 Gd 1.9– x W 2 O 9+ δ ) were prepared by high-temperature solid-phase method in this study. While ensuring the high near-infrared (NIR) solar reflectance, the anti-ultraviolet (UV) aging and antimycotic performance of rare earth given to pigment were evaluated, and its optical properties, microstructure and practical application effects were deeply explored. The results indicate that ternary entropy regulation changes the color of the pigment from white to yellow, significantly reducing the band gap from 3.28 to 1.90–1.87 eV. Specifically, the Ce 0.2 Ho 0.1 Gd 1.7 W 2 O 9+ δ pigment exhibits excellent chromatic properties ( L * = 73.79, a * = 20.21 and C * = 50.51) and a high NIR solar reflectance (96.23%). Infrared thermography confirms that it has a good cooling effect, with temperatures of 3.5 °C lower than the commercially available coating of similar color. Furthermore, the performance of multifunctional integration is that the pigments show enhanced absorption in the UVA (long-wave ultraviolet 320–400 nm) range, with an increase in average light absorption from 0.19 to 0.91 and a substantial increase in antimycotic rate from 42.86% to 97.46%. At the same time, this material has good acid and alkali resistance (Δ E * ≤ 2.41). The successful development of the multifunctional cool pigment materials opens a new way to energy-saving architectural wall coating materials.