The super hydrophobicity of ZnO nanorods fabricated by electrochemical deposition method

Electrochemical deposition method was employed to fabricate ZnO nanorods on zinc foil substrate in this paper. The structural observations of ZnO nanorods with different aspect ratios were carried out by field-emission scanning electron microscopy. The microstructures of ZnO nanorods were also characterized by X-ray diffraction and the changes in surface hydroxyls with electrochemical deposition time were analyzed by X-ray photoelectron spectroscopy. The study results show the aspect ratios of ZnO nanorods and the density of their surface hydroxyls are responsible for their superhydrophobicity. The fluorinated polymer coated ZnO nanorods showed an excellent superhydrophobic behavior with 167° contact angle of water droplet, which is larger than that of fluorinated polymer flat surface. The more the surface hydroxyls are, the more hydrophilic the surfaces are. Meanwhile, the larger the aspect ratio of ZnO nanorod arrays is, the larger its drophobicity is. The results of this study might pave a simple and feasibility pathway to the fabrication of superhydrophobic cleaning materials used in engineering fields.

Research Highlights► Different aspect ratios ZnO nanorods are fabricated by electrochemical deposition. ► Deposition time and temperature affect nanorod height instead of diameter. ► ZnO nanorods hydrophobicity will be increased with aspect ratios increasing. ► Surface larger hydroxyl density enables nanorods hydrophilic.