Development of an intense yellow-coloured BiVO4/ZrO2 composite coating for anticorrosion multifunctional cool roofing

Abstract

The development of durable coating materials with high solar reflectance without affecting the aesthetic characteristics is highly crucial to save energy. The present study explored a simple and cost-effective strategy for the development of BiVO₄/ZrO₂ composite coating (BVZ)-incorporated zinc phosphate for energy saving applications by enhancing the NIR reflectance properties along with ensuring an excellent corrosion-resistant performance. A high paint adhesive, anti-rust hopeite-rich phase was achieved by the growth of BVZ particles in the phosphating bath. The developed coatings were characterized using advanced instruments and the evaluation results agreed with each other. The existence of a more compact, dense, and uniform hopeite-rich optimized composite coating ensured high NIR reflectance (51.97%) and excellent chemical stability. The developed coating system displayed a remarkable response to the thermal-shielding experiment by achieving a significant temperature difference of 11.8 °C between the front and rear of the coating surface. The optimized coating showed enhanced NIR solar reflectance (58.97%) with excellent corrosion-resistant characteristics and corrosion rate (1.099 mmpy). Thus, the optimized BVZ composite with an improved intense yellow colour exhibited good NIR solar reflectance that makes it a potential candidate for cool colourants to reduce heat build-up.