Fe3O4/carbon black superhydrophbic coating exhibiting photothermal and efficient solar-assisted deicing properties

Abstract

Compared to conventional hydrophobic coatings, photothermal superhydrophobic coatings improve deicing by converting sunlight to heat, while face implementation barriers including dependence on costly nanomaterials, multi-step refined fabrication, and the potential environmental problems caused by common fluorinated hydrophobic agents. This work presents a fluorine-free, eco-friendly alternative fabricated using commercially available carbon black and low-cost Fe₃O₄ applied via simple air-spraying. This coating utilizes micron-sized Fe₃O₄ as the base material and nano-sized Carbon Black to form a nanotextured villous structure, establishing a stable micro-nano hierarchical architecture that enhances hydrophobicity. It achieves a water contact angle of 158.6° and a sliding angle of 4°. Under low-temperature conditions (−15 °C), the coating exhibits a delayed freezing time of 756 s. Furthermore, due to the porous micro-nano structure capturing light by promoting multiple reflections, coupled with the inherent photothermal synergy between Fe₃O₄ and carbon black, under 1 kW/m² irradiation, the coating not only reaches 56.5 °C within 300 s but also achieves complete large-scale deicing within 713 s. Crucially, the nanoparticles form interconnected bridges, maintaining robust mechanical properties while creating numerous air cavities that can hold water droplets, ensuring that the coating remains superhydrophobic even after immersion in acidic or alkaline solutions and sandpaper wear. This combination of superior surface properties, outstanding photothermal conversion, and excellent environmental and mechanical stability highlights its significant potential for anti-icing applications.