Fluorine-free photothermal superhydrophobic PDA-modified graphene oxide/PDMS coatings enabled by laser-induced hierarchical structures for efficient anti-/de-icing

Ice accumulation on outdoor engineering surfaces threatens operational safety in cold and humid environments, creating a need for durable coatings that combine passive anti-icing with active de-icing. Photothermal superhydrophobic coatings are promising, but their practical use is often constrained by fluorinated modifiers, weak coating adhesion, and the difficulty of achieving controllable and durable hierarchical surface structures. Here, we report a fluorine-free photothermal superhydrophobic PDA@GO/PDMS coating with laser-induced hierarchical micro/nanostructures. Polydimethylsiloxane (PDMS) provides a fluorine-free low-surface-energy matrix, while polydopamine-modified graphene oxide (PDA@GO) acts as an interfacially compatible photothermal component. Laser etching removes the resin-rich surface layer and generates hierarchical micro/nanostructures. These structures promote a low-adhesion Cassie–Baxter wetting state and create light-trapping microcavities that enhance multiple scattering and photothermal absorption. After optimizing the laser frequency, scanning speed, and scan repetition, the coating achieves a water contact angle of approximately 164° and a sliding angle below 5°. The laser-induced hierarchical structure prolongs droplet freezing to approximately 712 s and suppresses ice accretion under freezing rain conditions. Under 1 sun irradiation at −15 °C, the laser-etched coating heats to 12.3 °C within 300 s, and its efficient photothermal response combined with low ice adhesion enables rapid photothermal de-icing. The coating also maintains water repellency after mechanical damage, chemical exposure, UV aging, outdoor weathering, and repeated frosting/defrosting cycles, while showing applicability to various substrates and contaminated environments. This work demonstrates a durable fluorine-free strategy for developing laser-structured PDA@GO/PDMS coatings for photothermal anti-icing and de-icing applications.