Facile in-situ construction of multifunctional photothermal superhydrophobic composite membrane for effective anti-corrosion, anti-icing/de-icing and oil-water separation applications

Photothermal superhydrophobic surfaces possess remarkable characteristics, including extremely low adhesion to water and photothermal conversion ability, which enhances corrosion resistance, delays the formation of ice crystals, and can remove the ice from metallic surfaces through photothermal conversion. However, the fabrication strategies in previous reports require expensive equipment or lengthy preparation times. In this study, a multifunctional photothermal superhydrophobic composite membrane on copper mesh was prepared by a simple two-step electrodeposition combined with one-step adsorption strategy. Firstly, a rough interface composed of CoFe-LDH nanoflowers was formed on the surface of copper mesh via the first step of electrodeposition. Secondly, a MoS2 photothermal membrane was constructed above the rough interface after second step of electrodeposition. Finally, the adsorption of stearic acid molecules endowed the composite membrane with superhydrophobicity. The as-prepared Cu/CoFe-LDH/MoS2/SA mesh achieved impressive anti-corrosion performance, with high corrosion inhibition efficiencies of 98.7%, 94.9%, and 93.1% in brine, acidic, and alkaline environments, respectively. Furthermore, the anti-icing tests indicated that the Cu/CoFe-LDH/MoS2/SA mesh surfaces exhibited a considerably longer freezing delay time of 1441 s compared with the original copper mesh at -10 degrees C. Moreover, due to its exceptional photothermal conversion performance, ice droplets on the Cu/CoFeLDH/MoS2/SA mesh surface fully melted at 10 s, and the complete evaporation of the water droplets required only 262 s at -10 degrees C under NIR laser irradiation. In addition, the Cu/CoFe-LDH/MoS2/SA mesh also exhibited exceptional separation efficiency, exceeding 99.5 % for various oily liquids, and maintains over 99.0 % efficiency even after 50 separation cycles. Therefore, the as-prepared multifunctional photothermal superhydrophobic surface is prospective for anti-corrosion, anti-icing/de-icing and oil-water separation applications due to the advantages of facile construction, low-cost, excellent superhydrophobicity and superior photothermal capability.