Transparent Photothermal Slippery Surface Based on Monolayer Self‐Assembled MXene Film for Anti‐Fogging and De‐Icing

ABSTRACT Transparent surfaces with autonomous anti‐fogging and de‐icing capabilities are critical for smart windows, eyewear, and optical sensors. Existing solutions relying on wettability engineering or bulk photothermal materials suffer from poor transparency, contamination vulnerability, or energy inefficiency. Here, we report an ultrathin (2.5 nm) MXene film self‐assembled at liquid‐liquid interfaces via Marangoni flow, achieving 82.5 % visible transparency while enabling a high photothermal conversion effect (ΔT∼25.1°C ± 2.9°C) under 100 mW cm −2 . It is due to the unique percolative MXene network formed at ultralow loading (< 0.1 mg cm −2 ), leveraging the critical percolation thresholds to reconcile ultraviolet (UV, 300–400 nm) and near‐infrared (NIR, 700–2000 nm) absorption with visible transparency (82.5 %, 400–700 nm), which overcomes the trade‐off between solar harvesting and transparency. Therefore, coupled with a silicone oil‐infused slippery surface, the composite coating (TPSS) exhibits rapid ice shedding (85 s at −20°C under 1 sun) and fog resistance (at 90 % humidity). Outdoor demonstrations (Beijing, 2.1°C) on eyewear and architectural models validate frost suppression, rapid de‐icing, and mechanical flexibility. This scalable, sunlight‐powered platform bridges transparency and icephobicity for next‐generation optical devices.