Core-shell particles for devising high-performance full-day radiative cooling paint

Radiative cooling as a passive cooling methodology by spontaneously reflecting sunlight and radiating excessive heat to the outer space, is characterized with no emission and zero energy consumption. Although extremely appealing, there remains strong need for high-performance, large scalable, cost-effective and highly compatible radiative cooling materials. Herein, we report a core-shell particles (CSP) based radiative cooling coating (RCC) for effective full-day radiative cooling with ease of fabrication, inexpensive raw material and excellent compatibility to multiple application occasions. Core-shell particles with multi-scaled size induce efficient light backscattering, accounting for the ultrahigh solar reflectivity (0.96), along with a high thermal emissivity (0.94) in the atmospheric window originated from intrinsic infrared phonon vibrational characteristics of silica and willemite phase. Our RCC features superb flexibility like commercial white coating (CWC), but exhibits distinct radiative cooling property, with temperature drop of 4.1 °C and 5.3 °C in the daytime and nighttime respectively, and integrated with unique anti-fouling ability, our work holds great potential in promoting large-scale applications of radiative cooling coating commercially and engineeringly.