Fabrication of a bionic superhydrophobic metal surface by sulfur-induced morphological development

We describe the fabrication of lotus leaf-like superhydrophobic metal surfaces by using the simple electrochemical reaction of Cu or Cu–Sn alloy plated on steel sheets with sulfur gas, and subsequent perfluorosilane treatment. The microstructure of these surfaces was obtained through the nonelectric chemical plating of the copper onto the steel sheets, and the nanotexturing of the surfaces was achieved via an electrochemical reaction of copper in a sulfur-containing environment at 150 °C, resulting in the formation of a copper sulfide nanostructure on the microstructure. The chemical composition of this metal surface was confirmed using X-ray photoelectron spectroscopy. The water contact angles of the bionic metal surfaces were found to be over 160°, and this surface exhibits a low contact angle hysteresis. To our knowledge, this is the first time this approach has been used with a simple chemical reaction to fabricate an artificial superhydrophobic metal surface.