Robust superhydrophobic fabric via UV-accelerated atmospheric deposition of polydopamine and silver nanoparticles for solar evaporation and water/oil separation

Polydopamine (PDA) inspired by mussel plays a unique role in surface modification due to its strong adhesion to virtually all kinds of materials and the subsequent functionality. However, the deposition of PDA and its subsequent metallization in bulk solution is slow and thus the surface modification based on PDA is not efficient. Herein, by atmospheric deposition with the aid of ultraviolet (UV) irradiation, a process is proposed to facilitate the fast deposition of PDA and silver nanpparticles (Ag NPs) on cotton fabric. The word “fast” means that efficiency of the overall deposition is increased by 45 times. Fabric with PDA and Ag NPs is further modified by dodecyl mercaptan (DT) and turns to be superhydrophobic. Ag NPs play multiple roles in the fabrication and application of the superhydrophobic fabric, viz., enhancing the hydrophobicity and photothermal effect of the fabric. Due to its superhydrophobicity and excellent photothermal effect, the fabric floating on water can harvest solar energy to facilitate the local evaporation of seawater. The evaporation rate is 1.66 kg/(m2·h) and the solar energy conversion efficiency is 91%. As the oil–water separation membrane, the separation efficiency of oil–water mixture is more than 96%, and the oil flux is more than 12 m3·m−2·h−1. Overall, this is a story from sea to sea. PDA inspired by the sea creature of mussel is quickly deposited on the fabric and serves as a platform for further deposition of silver and modification with DT, and the so-obtained superhydrophobic sample can be used to solve the marine problems such as solar evaporation and oil/water separation.