Fabrication of Superhydrophobic Multiwalled Carbon Nanotube@SiO ₂ Aerogels Coated Aluminosilicate Fiber Paper for Photothermal Anti‐Icing and Thermal Insulation

Aluminosilicate fiber paper (Al 2 SiO 5 FPs) is widely used as an insulation material; however, its inherent hydrophilicity makes it vulnerable to water infiltration, which significantly reduces its insulating performance in high‐humidity and freezing environments. Therefore, enhancing its water repellency and anti‐icing capabilities is essential. In this work, a photothermal superhydrophobic Al 2 SiO 5 FP coated with MWCNT@SiO 2 aerogels is presented featuring highly porous hierarchical micro/nanostructures, fabricated using a simple, rapid, and fluorine‐free spraying technique. The as‐prepared superhydrophobic surface exhibits excellent water repellency, superior self‐cleaning ability, and outstanding mechanical and chemical durability. Notably, it retains high insulation performance even under wet conditions. Furthermore, the surface demonstrates remarkable photothermal properties, achieving ≈95.7% light absorption. Under one‐sun irradiation (1 kW/m 2 ), it reaches a peak temperature of 102.6°C, confirming efficient solar‐to‐thermal energy conversion. Anti‐icing evaluations reveal that the surface delays ice formation by a factor of 3.7 compared to the pristine Al 2 SiO 5 FP substrate, indicating robust passive anti‐icing capability. Subsequent photothermal de‐icing tests demonstrate that the surface effectively melts ice layers, facilitating rapid and energy‐efficient ice removal. Consequently, this multifunctional superhydrophobic coating greatly broadens the practical applications of aluminosilicate fiber paper in harsh environments.