Binding-energy regulated assembling of mixed-dimensional pearl-string heterostructure aerogel for efficient passive...

Radiative cooling aerogels have significant application potential in sustainable and spontaneous thermal management, as well as the mitigation of the urban heat island effect. Although aerogels are recognized by their large scattering interfaces, their monotonous gas-solid interface geometry imposes constraints on their anti-solar radiative performance. Here, we present a facile and extensible single-step binding-energy regulated assembly strategy to construct pearl-string heterostructured aerogels (PSHA) with unique mixed-dimensional interface features that significantly extend the solar reflectance and scattering capabilities. By incorporating the infrared-emitting chemical bonds with the pearl-string micro-nano architectures, the PSHA achieves exceptional solar reflectance of 96.8 % across a 0.3-2.5 μm wavelength range, coupled with strong thermal emissivity of 98.5 % within the atmospheric window (8-13 μm), which enables remarkable outdoor daytime cooling power reaching 123.7 W m^-2 owing to the enhanced near-field Mie scattering and far-field geometric optics of the pearl-string heterostructure. Additionally, PSHAs exhibit a high specific surface area, excellent mechanical properties, outstanding thermal insulation performance with a low thermal conductivity of 32 mW m^-1 K^-1, and remarkable environmental adaptability, all of which significantly expand their applicability in radiative cooling applications.The proposed binding-energy-regulated mixed-dimensional heterostructure construction strategy not only provides a generalizable pathway for developing high-performance radiative cooling materials but also establishes a new paradigm for integrated multifunctional applications, including radiative cooling, energy absorption, thermal insulation, and sensing technologies.