Large-area unmodified superhydrophobic copper substrate can be prepared by an electroless replacement deposition

Using an electroless replacement deposition method, large-area superhydrophobic metal substrate could be obtained. The superhydrophobic surfaces were prepared via a replacement reaction between copper substrate and HAuCl(4) solution. The roughness of the copper substrate increased much after the replacement reaction. X-ray powder diffraction (XRD) pattern and energy dispersive X-ray (EDX) spectroscopy have proved that gold, CuCl and Cu(2)O formed on the surface of copper substrate after the replacement reaction. The surface showed remarkable superhydrophobic properties with a contact angle higher than 150 degrees without any modification with a self-assembled monolayer (SAM) of long chain thiol or perfluoro molecules.