A tree-frog-inspired superhydrophobic composite coating integrating photothermal/electrothermal heating and reversible thermochromism for adaptive thermal regulation and high-efficiency de-icing

The escalating energy demand and growing frequency of extreme weather events have intensified environmental burdens and building safety risks, underscoring the urgent need for smart coatings that couple photothermal effects with adaptive thermal management. Conventional photothermal systems often suffer from uncontrollable overheating under intense solar irradiation and insufficient heating for efficient de-icing in low-light conditions. To overcome these limitations, we present a durable, all-climate intelligent coating that integrates photothermal and electrothermal heating, adaptive temperature regulation, and superhydrophobicity via a robust bilayer design. At low temperatures, the black adaptive layer, combined with the highly absorptive carbon-based underlayer, achieves a solar absorptance of 94.7%, enabling the surface temperature to exceed 20 °C within 60 s under 1 sun (1 sun = 1000 W/m²). At elevated temperatures, the adaptive layer transitions from black to light yellow, effectively shielding the carbon-based photothermal layer and transforming the surface into a highly reflective state with a solar reflectance of 61.1%. The resultant reflectance shift (ΔR_s = 55.8%) facilitates effective thermal regulation and prevents overheating. Under low or absent illumination, the carbon-based underlayer delivers stable electrothermal heating, achieving rapid temperature elevation at a low power density of 0.10 W/cm². Benefiting from its bilayer micro/nanostructured architecture, the coating maintains superhydrophobicity after rigorous tests—including abrasion, immersion, water impact, and tape-peeling—demonstrating exceptional durability. This intelligent coating, featuring rapid low-temperature heating, active high-temperature cooling, and all-weather adaptability, offers a promising strategy for energy-efficient buildings and anti-icing applications in extreme climates.