Triple-Scale Photothermal Superhydrophobic Anti/De-Icing Coating with Enhanced Mechanical Robustness and Chemical Stability via Introducing Low-Cost Green Petroleum Coke Particles

Icing can cause huge inconveniences in daily life and even safety problems. Constructing photothermal superhydrophobic coatings is considered as a promising strategy for inhibiting ice accretion due to their good passive anti-icing and active de-icing capability. However, such coatings usually involve high-cost photothermal materials, toxic fluorinated reagents, fragile nanostructures, and inferior chemical stability. This study proposes a novel strategy for fabricating a triple-scale photothermal superhydrophobic coating (TPSC) through a simple impregnation method using inexpensive green petroleum coke (GPC) particles (submillimeter scale) and nanoscale graphite (Gr) particles. The TPSC is superhydrophobic with a water contact angle of 160.3° and possesses an excellent photothermal property with a temperature increase of ∼42 °C under 80 mW/cm² irradiation with sunlight. Owing to its superhydrophobicity, the freezing time of the TPSC is prolonged by a factor of 7.87 compared with that of bare aluminum. Benefiting from the excellent photothermal effect, an ice droplet on the coating can be melted within 180 s under 60 mW/cm² irradiation with simulated sunlight. Furthermore, the incorporation of GPC not only effectively protects the embedded Gr particles within the microgrooves but also stabilizes the Cassie-Baxter state, thereby significantly enhancing the mechanical robustness and chemical stability of the TPSC. More importantly, this approach avoids the carbon emissions associated with the calcination of GPC, achieving an environmentally friendly and cost-effective application. This study can be expected to offer an efficient and sustainable anti-icing and de-icing strategy for outdoor equipment.