Reversible wettability between superhydrophobicity and superhydrophilicity of Ag surface

We present a facile one-step method to fabricate superhydrophobic Ag surface by electrodeposition without using any low surface energy reagent. The water contact angle of the prepared surface is 167.1 degrees and the sliding angle is only 0.5 degrees after heat treatment. It is demonstrated by the field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses that the dendrites of rough micro-nanostructure combined with the spontaneously adsorbed hydrocarbon make the surface exhibit superhydrophobicity. However, the superhydrophobic Ag surface becomes superhydrophilic when the surface is irradiated by UV light for several hours. It recovers superhydrophobicity after further heat treatment and can successfully implement the reversible wettability transition between superhydrophobicity and superhydrophilicity for several cycles.