Nano Energy

Radiative cooling, Building cooling energy saving, Nanotwins, Glass-ceramic, Mechanical properties

Porous ceramic based radiative cooling materials offers an energy-efficient solution for buildings cooling. Yet inter-connected micropores in those materials not only weaken their mechanical strength and resistance to pollutant penetration, but also inhibit the compatibility with structural colors. Herein, ultra-high reflective SiO2-ZrO2 glass-ceramics are prepared by introducing lamellar m-ZrO2 nanotwins into SiO2 matrix. m-ZrO2 nanotwins are proven effective in enhancing the reflection of sunlight, which provides an alternative to the Mie scattering of pores. The glass-ceramics exhibit a solar reflectivity of 0.98 at a low porosity of 17.62%, while maintaining excellent mechanical properties. Based on self-assembly and an annealing process, long-range ordered SiO2 microspheres arrays are deposited to the surface of the glass-ceramics, yielding structural colors and elevated reflectivity up to 0.99. The green structural colored glass-ceramics with highest reflectivity achieve 3.97 ℃ daytime cooling performance under solar irradiation of 672 W m-2. When used as the envelope of a typical four-story midrise apartment building, such glass-ceramics demonstrate cooling energy saving by at least 15% and the highest annual electricity cost saving of 44,136 CNY (6,199 USD) across 32 representative cities in China. The developed SiO2-ZrO2 glass-ceramics hold tremendous potential for use in advanced radiative cooling, particularly of buildings.

Jieyan Zhao

Qian Wan,Ning Qin,Jiangtao Li

Wenjie Luo,Xuanlin Pan,Qing Meng,Huakang Zhang,Jing Xia,Xiangling Ren,Lei Kang

Journal paper

111700

17.1

No

2026-01

SCI