Bioinspired superhydrophobic surfaces with various properties have aroused enormous concerns. However, present artificial superhydrophobic surfaces usually exhibit a single function, and their fabrication processes excessively depend on the toxic and expensive fluorine-containing chemicals. With the purpose of tackling the issues, a fluorine-free and economical approach was adopted to construct a multifunctional superhydrophobic Ni₃S₂ micro-nanostructured coating, and the resulting water contact angle (WCA) and sliding angle (SA) were 165° and 3°, respectively. Therefore, the coating was significantly repellent to the water penetration, and the falling droplets could bounce off the coating surface without being pinned. The greater WCA and lower SA of Ni₃S₂ micro-nanostructured coating allowed the surface to resist the adhesion of solid or liquid contaminations. In addition, it was confirmed that this superhydrophobic Ni₃S₂ micro-nanostructured coating was able to effectively hinder the surface from being affected by the detrimental scaling and condensation, thereby extending the service life of the substrates. Besides, to release the serious damage caused by the frequent oil leakages and ever-increasing oily sewage, the superwetting Ni₃S₂ micro-nanostructured coating were employed to achieve efficient oil/water separation, even functioning well in separating complex mixtures, including oil-hot water mixtures, oil-in-water emulsions and immiscible organic solvents. Moreover, in terms of the semiconductor properties, Ni₃S₂ micro-nanostructures showed photocatalysis to degrade water-soluble dyes targeting to further relief the water pollution. Furthermore, the superhydrophobic Ni₃S₂ micro-nanostructures with a narrow bandgap (2.1 eV) could harvest sufficient solar energy and promote a surface temperature rise up to 77.06 ℃. The response to sunlight was repeatable and the generated heat was conducive to inhibiting undesirable freezing. Meanwhile, this special photothermal effect had a beneficial effect on facilitating the interface evaporation, which could alleviate the urgent freshwater scarcity and pollution. These presented works are expected to supply promising inspirations for future applications in superhydrophobic materials.

superhydrohobic coatings,photothermal effect,oil-water separation,Ni3S2 micro-nanostructure