Spray-Coated Superhydrophobic Overlayer with Photothermal and Electrothermal Functionalities for All-Weather De/anti-icing Applications

High-performance de/anti-icing overlayers which can be deposited on diverse surfaces offer great potential in many industrial settings and daily life, yet a versatile overlayer applicable to all-weather conditions (high humidity, low temperature, raining, snowing, etc.) is in high demand for practical applications. This study presents the fabrication and application of a superhydrophobic overlayer with a bioinspired hierarchical surface which additionally possesses photothermal and electrothermal functionalities, so it can operate as a de/anti-icing layer in extreme environments. The overlayer, with a papilla-like microstructure similar to that of a lotus leaf, features polydopamine-decorated layered basic zinc acetate microparticles distributed in the framework of multiwalled carbon nanotubes. Specifically, the overlayer is superhydrophobic, and its capability of suppressing the condensation of water droplets and growth of ice crystals is verified by both in situ environmental scanning electron microscopy observations and freezing experiments. Moreover, the overlayer can be warmed up to 74 and 105 °C under the excitation of sunlight and direct current bias, respectively, which is sufficiently high for deicing in severe weather. It is worth mentioning that the overlayer is produced by a spray-coating technique; therefore, it is suitable for large-scale deployment on arbitrary substrate materials. The findings provide insights into a new strategy for engineering multifunctional overlayers and can lead to expanding applications of composite coatings.