Superhydrophobic surface from Cu-Zn alloy by one step O2 concentration dependent etching.

The article reports on a very simple method to fabricate superhydrophobic surfaces with Cu-Zn alloy via changing the local oxygen concentration and formation of oxygen difference cell, which can be readily realized by covering or contacting the Cu-Zn alloy surface with a glass slide. This superhydrophobic film comes from the formation of a flower-like hierarchical structure due to the accelerated alloy etching. In contrast, the white film grown in the un-covered area showed a much lower hydrophobicity due to its different morphology. These superhydrophobic surfaces or superhydrophobic-hydrophobic surfaces are expected to find applications in making self-cleaning alloy surface, in metal anticorrosion, and in biomineralization, etc.