Ultrablack, Superhydrophobic Coating for Efficient Anti-Icing and De-Icing in Humid Cold Environments

Photothermal superhydrophobic coatings merge sunlight-driven heating with water repellency and are therefore regarded as a promising strategy to prevent ice accumulation on infrastructure. State-of-the-art photothermal superhydrophobic coatings, however, rely on complex fabrication and hazardous chemicals or exhibit insufficient performance under realistic low-temperature, high-humidity conditions. Herein, we report a facile and scalable approach for fabricating an ultrablack and superhydrophobic coating by spraying a mixture of porous reduced graphene oxide microspheres (PGM) and a fluororesin onto a precured polydimethylsiloxane (PDMS) layer. The as-prepared coating exhibits exceptional broadband light absorption (up to 99.5%) and outstanding photothermal conversion efficiency, reaching 86.9 °C under 1.0 kW·m^-2 illumination within 60 s. Simultaneously, it displays robust superhydrophobicity with a water contact angle (CA) >150°, imparting self-cleaning capability. These combined properties endow the coating with remarkable anti-icing and de-icing performance. Even under a temperature of -10 °C and 90% humidity, the coating delays freezing for more than 5 h, approximately 900 times longer than bare aluminum. Furthermore, under 1.0 sun illumination, it sheds all ice within 55 s and a 1.5 mm ice layer within 105 s under 0.5 sun. Moreover, the coating shows excellent stability in acidic and alkaline environments and exhibits superhydrophobic and self-cleaning properties, which prevent the degradation of the coating's optical performance due to contamination by dust and dirt. This work provides a promising, real-world anti-/de-icing route by virtue of the convenient preparation, large-scale sprayability, and reliable adhesion of the PGM-FP coating on diverse substrates.