Cost effective 24-h radiative cooler with multiphase interface enhanced solar scattering and thermal emission. (June 2022)

• Record Type: Journal Article
• Authors: Zhang, Shuai; Wu, Zhenhua; Liu, Zekun; Lin, Hengxing; Lin, Zeyu; Li, Jiayi; Kong, Shuang; Hu, Zhiyu
• Is Part Of: Materials today communications. Volume 31(2022)
• Publication Date: 2022-06
• Subjects: Thermal emitter -- Radiative cooling -- Hybrid material -- Multiphase -- Atmospheric window; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2022.103398
• Languages: English
• ISSNs: 2352-4928

Abstract

Abstract: Passive radiative cooling is an emerging energy-free pathway that radiates the emission of heat from the earth to cold space (3 K) through an atmosphere transparent window (7–14 µm). Recently, this technology has attracted great interest in residential and industrial applications. However, critical challenges remain for 24-h radiative cooling due to the unwanted solar heating effect in the daytime. The complex manufacturing process and high price also result in a cost barrier for large-scale applications. Here, an easy-prepared and cost-effective radiative cooler (RC) was processed which consists of polydimethylsiloxane (PDMS) and SiO2 microspheres based on cellulose nanofibers (filter paper) with a backing silver (Ag) mirror for mass production. This whitish hybrid material exhibited high reflectance of 91% in the AM 1.5 solar spectrum (0.2–2.5 µm) and high thermal emissivity of 90% in the atmospheric window, which was enhanced by the randomized multiphase interfaces. Moreover, it can accomplish 24-h continuous outdoor cooling with an efficient average temperature reduction of 5 °C, especially 6.5 °C in the nighttime. Overall, this work provided a new approach to promote 24-h radiative cooling as a next-generation green energy technology. Graphical Abstract: ga1 Highlights: A easy-prepared and cost-effective way to fabricate radiative cooler. Multiphase interfaces backscattering achieves low solar absorption. High mid-infrared emissivity can be enhanced by multiscale networks and multiphase interfaces. Efficient 24-h radiative cooling with a average temperature drop of ~5 °C.