Bio-inspired fabrication of copper oxide nanowire films with switchable wettability via a facile thermal oxidation method

Abstract

CuO nanowire surfaces with micro/nanometer structures were constructed on a copper substrate by a facile thermal oxidation method, the CuO nanowires have micro/nanometer structures similar to those of the hind wings of water boatmen. The as-fabricated CuO nanowire surface is superhydrophilic, and the water contact angle on it is less than 5°. Modifying the CuO nanowire surface with dodecanethiol (DDT) switched the wettability from superhydrophilic to superhydrophobic with a water contact angle of 154° and a glide angle of 4°. In addition, the original superhydrophilic behavior was regained via annealing at 300 °C due to the desorption of the low surface energy monolayer of DDT. The transition between superhydrophobicity and superhydrophilicity could be switched by alteration of the adsorption/desorption of the DDT monolayer. Compared with the superhydrophilic CuO nanowire surface, the superhydrophobic CuO nanowire surface exhibits better corrosion resistance and self-cleaning properties.