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The conventional way to fabricate current sub-ambient daytime radiative cooling (SDRC) systems is to maximally suppress the cooler's solar absorption and substantially improve its selective emissivity only in the atmospheric transparency window. This greatly limits the selection of materials and their practical applications. In this paper, an alternative method, which combines sunlight-triggered fluorescent cooling, particle scattering, and broadband infrared radiation, was presented for creating serial eco-friendly coatings with the SDRC effect with conventional cost-effective building materials. The presence of conventional fluorescent pigments in the coating composition increased the effective direct-normal solar reflectance via sunlight-excited fluorescent emissions to the level required for SDRC. When applied to various substrates, the serial coatings exhibited distinct SDRC effects under direct and strong sunlight in typical temperate monsoon climate regions such as Beijing. The observed sub-ambient temperature reduction of the coating with yellow–green fluorescence over an aluminium plate was 3.5 °C under a peak solar intensity of 996 W/m2, yielding a cooling power of 45.7 W/m2 under a peak solar intensity of 981 W/m2. Compared with the conventional cool white coatings, the large-scale application of the coating to urban surfaces is predicted to reduce a city's air temperature by approximately 1 °C and thereby decrease the Heat Island Intensity. Additionally, the method proposed in this paper was generic and expanded the SDRC design paradigm, thereby promoting SDRC as a viable energy-efficient technology. Image 1 • Fluorescent emissions increase the effective solar reflectance to an ideal level. • Fluorescent cooling is crucial for sub-ambient daytime radiative cooling (SDRC). • FR coatings over various substrates exhibit distinct SDRC effect. • The SDRC effect on an aluminium plate is 3.5 °C on a clear hot sunny day. • The cooling power is 45.7 W/m2 under a peak solar intensity of 981 W/m2. [ABSTRACT FROM AUTHOR]

Waterborne and solvent-based coatings with prominent passive subambient daytime radiative cooling (RC) coatings were fabricated to conserve cooling energy in the summer. Concurrently, water- and alcohol-based superamphiphobic self-cleaning coatings were manufactured and introduced into the RC coatings as topcoats. The contact angles of water and n -hexadecane of the superamphiphobic topcoat containing coating systems were 163.4° and 151.4°, respectively; additionally, the sliding angles of water and n -hexadecane of these systems were 2° and 9°, respectively. Moreover, the introduction of a transparent superamphiphobic topcoat to the RC coatings did not affect their originally high solar reflectance but improved their emissivity values in the atmospheric transparency window, wavelengths between 2.5 and 24 μm, and the entire infrared spectrum due to the presence of plenty of silicon-oxygen bonds formed via hydrolysis and/or alcoholysis reactions and the subsequent co-polycondensation of tetraethoxysilane and 1H,1H,2H,2H-perfluorodecyltriethoxysilane. The solar reflectance of the coating system was 0.986, which is the highest recorded worldwide. The emissivity of the superamphiphobic RC coatings in the atmospheric transparency window was 0.954. The superamphiphobic RC coatings possessed excellent static and dynamic non-wetting capabilities, significantly improving their water resistance, waterproofing properties, and anti-graffiti performance. Additionally, the superamphiphobic RC coatings exhibited outstanding self-cleaning properties, preventing the coating surfaces from being contaminated by dust, soiling, grime, and water/oil-soluble pollutants, thereby enabling them to maintain an extremely high solar reflectance. Water- and alcohol-based superamphiphobic radiative cooling coatings with solar reflectance up to 0.986 were fabricated. The emissivity in the atmospheric transparency window and thereby the overall emissivity were increased to 0.954 and 0.96, respectively, due to the introduction of transparent superamphiphobic topcoats. The contact angles of water and n -hexadecane were 163.4°and 151.4°, respectively, while the sliding angles of water and n -hexadecane were 2°and 9°, respectively. [Display omitted] •The superamphiphobic coating with subambient daytime radiative cooling was produced. •The solar reflectance of the coating was up to 0.986 •The coating's emissivity in the atmospheric transparency window was 0.954 •The coating's contact angles of water and n-hexadecane were higher than 150°. •The coating's sliding angles of water and n-hexadecane were lower than 10°. [ABSTRACT FROM AUTHOR]