A Versatile Strategy for Concurrent Passive Daytime Radiative Cooling and Sustainable Energy Harvesting

Abstract

Developing versatile systems that can concurrently achieve energy saving and energy generation is critical to accelerate carbon neutrality. However, challenges on designing highly effective, large scale, and multifunctional photonic film hinder the concurrent combination of passive daytime radiative cooling (PDRC) and utilization of sustainable clean energies. Herein, a versatile scalable photonic film (Ecoflex@h‐BN) with washable property and excellent mechanical stability is developed by combining the excellent scattering efficiency of the hexagonal boron nitride (h‐BN) nanoplates with the high infrared emissivity and ideal triboelectric negative property of the Ecoflex matrix. Strikingly, sufficiently high solar reflectance (0.92) and ideal emissivity (0.97) endow the Ecoflex@h‐BN film with subambient cooling effect of ≈9.5 °C at midday during the continuous outdoor measurements. In addition, the PDRC Ecoflex@h‐BN film‐based triboelectric nanogenerator (PDRC‐TENG) exhibits a maximum peak power density of 0.5 W m−2. By reasonable structure design, the PDRC‐TENG accomplishes effective wind energy harvesting and can successfully drive the electronic device. Meanwhile, an on‐skin PDRC‐TENG is fabricated to harvest human motion energy and monitor moving states. This research provides a novel design of a multifunctional PDRC photonic film, and offers a versatile strategy to realize concurrent PDRC and sustainable energies harvesting.

Recent advancements in radiative cooling textiles for personal thermal management

“…The application of smart clothing, designed with PRC structural textiles to regulate the human microenvironment, presents a promising solution for efficient PTM. 14–18 To date, many RC textiles, including photonic membranes, 19,20 fibrous films, 21,22 metamaterials, 23,24 hybrid nanoporous polymers, 25–28 and colorful fluorescent materials, 29,30 have been utilized for daytime RC functionality.…”

A Novel Multifunctional Photonic Film for Colored Passive Daytime Radiative Cooling and Energy Harvesting

“…[ 46 ] Integrating PDRC film into the design of TENG is an emerging new research hotspot since it is an efficient way to simultaneously achieve energy saving and energy generation. [ 47,48 ] Considering the practical application requirements, the solar reflectance and the triboelectric property of the PDRC film should be further enhanced. Generally, dielectric modulation is a viable strategy to promote the surface charge density and trapping capability of triboelectric materials, which is beneficial to improve the energy harvesting efficiency of TENG.…”

Construction of Reversible Cross-Linked Polyurethane Composite Coating with Recyclability and Passive Radiative Cooling Performance

“…Passive daytime radiative cooling (PDRC) has become a frontier in various fields of functional coatings, solar cells, and thermoelectric generators. 1,2 It is an emerging cooling technology that can reflect sunlight in the solar spectral range (0.3−2.5 μm) and spontaneously emit heat directly into the atmospheric environment through the atmospheric transparent window (8−13 μm). 3,4 Recently, PDRC polymer coatings have attracted the extensive attention of many researchers and practitioners to mitigate global energy demands and climate impacts.…”

“…Passive daytime radiative cooling (PDRC) has become a frontier in various fields of functional coatings, solar cells, and thermoelectric generators. , It is an emerging cooling technology that can reflect sunlight in the solar spectral range (0.3–2.5 μm) and spontaneously emit heat directly into the atmospheric environment through the atmospheric transparent window (8–13 μm). , Recently, PDRC polymer coatings have attracted the extensive attention of many researchers and practitioners to mitigate global energy demands and climate impacts. − Polyurethane, especially cross-linked polyurethane, is one of the most popular matrix materials applied in coatings such as leather, synthetic leather, roof and exterior walls of buildings, and wood and metal protection, due to the easy processing, cost-effectiveness, hydrophobicity, cold resistance, and durability. − However, most of the commonly used polyurethanes are often short of high-enough solar reflectance and cannot be directly used for radiation cooling coatings …”