Superhydrophobic pure silver surface with flower-like structures by a facile galvanic exchange reaction with [Ag(NH_3)_2]OH

摘要

Superhydrophobic pure silver film composed of flower-like microstructures built by interconnected silver nanoplates on a copper plate without any modification was prepared by a facile galvanic exchange reaction between the aqueous [Ag(NH_3)_2]OH and the copper plate, giving rise to a contact angle as high as 157°. Superhydrophobic surfaces, inspired by water-repellent surfaces in nature, have attracted a great deal of interest for fundamental research and practical applications. The superhydrophobic surfaces are usually fabricated via two approaches: creating micro-nanostructures on intrinsically hydrophobic substrates, or chemically modifying the micro-nanostructured surfaces (either hydrophobic or hydrophilic) by materials with low surface free energy. Many elegant methods, such as template synthesis, electrochemical deposition, and so on, have been developed to construct micro-nanostructures on a hydrophilic substrate. To the best of our knowledge, however, it still remains a great challenge to create a superhydrophobic pure metal surface without any modification, as the free metal surface is generally hydrophilic with high surface energy.