Construction of colorful super-omniphobic emitters for high-efficiency passive radiative cooling

A series of colorful super-omniphobic radiative cooling emitters with layered structures has been constructed by two-step process. The colors of the emitters contained three primary colors (red, green, and blue) to obtain desired aesthetics, and the pigments used were selected by theoretical analysis. The emitters could reflect above 90% of the near infrared light and display infrared emission above 85% within atmospheric window. The as-prepared super-omniphobic colorful radiative cooling emitters all obtained wettability of water contact angles above 160° and oil contact angles above 150°. Besides, super-omniphobicity endowed the emitters with self-cleaning properties. Moreover, the emitters could remain the optical performance and super-omniphobicity after abrasion and UV irradiation. For the outdoor cooling measurement within 2 days, the emitters could drop the temperature down to 5–10 °C below those of the reference samples during daytime and 3–5 °C during the nighttime. This research paves a new way to synchronously achieve efficient durable radiative cooling and aesthetic performance.