Durable and Ultra‐Black Superhydrophobic Coatings for High‐Efficiency Photothermal Applications Under Harsh Conditions

Abstract Efficient solar‐thermal conversion is crucial for applications including de‐icing, energy harvesting, and thermal regulation in outdoor environments. However, most existing photothermal coatings suffer from limited light absorption and poor mechanical durability, leading to performance degradation under cold and low‐irradiance conditions. Here, a durable ultra‐black superhydrophobic coating is reported and fabricated through a simple spraying process, in which carbon nanotubes (CNTs), titanium nitride nanoparticles (TiN NPs), and a fluorocarbon silane are incorporated into a polydimethylsiloxane (PDMS) matrix. The resulting hierarchical micro/nanostructure exhibits an exceptionally low reflectance of 0.66%, excellent water repellency, and strong anti‐icing capability. The micro/nanostructured surface morphology efficiently traps incident light, while the TiN and CNTs form a synergistic system where localized surface plasmon resonance (LSPR)‐induced near‐field enhancement significantly amplifies the photonic absorption, thereby improving broadband light harvesting and photothermal conversion. Under 1 sun irradiation, the coating rapidly heats to 70.1 °C, achieving efficient defrosting and de‐icing. Even at −10 °C under 0.3 sun, the temperature rise is fourfold higher than that of TiN‐free coatings. Moreover, TiN NPs enhance CNT dispersion and strengthen the filler‐matrix interface, yielding excellent durability. This work provides a simple and scalable strategy for multifunctional photothermal coatings with reliable performance in energy‐limited cold environments.