Recyclable Dry‐Processed PTFE Composite Films for Passive Radiative Cooling With Interfacial Energy Harvesting

ABSTRACT Passive radiative cooling (PRC) enables electricity‐free sub‐ambient cooling by emitting thermal radiation through atmospheric transparency windows. However, most high‐performance PRC materials still rely on solution‐based processing, which consumes solvents, releases volatile organic compounds (VOCs), and weakens their sustainability. Herein, we report a reprocessable dry‐processing strategy that uses in situ polytetrafluoroethylene (PTFE) fibrillation to construct an entangled fibril–micro/nanoparticle entangled network. The resulting hierarchical photonic architecture with high solar reflectance (93.3%) and mid‐infrared emissivity (91.1%), achieving an average sub‐ambient cooling of 5.5–10.6°C at relative humidities of 28.7%–50.4%. In addition, the film exhibits excellent thermal stability (decomposition temperature > 500°C) and environmental durability (540 h of accelerated UV aging). To address the low utilization of PRC films in rainy conditions, the dielectric property of the film is easily exploited to construct solid–liquid triboelectric nanogenerator (TENG), with a peak power density of 89.85 W m −2 , for raindrop energy harvesting. Furthermore, the film maintains stable optical, cooling, and triboelectric performance after repeated recycling. This low‐carbon recyclable strategy provides a scalable approach for all‐weather energy management and sustainable green technologies.