Single-step prepared hybrid ZnO/CuO nanopowders for water repellent and corrosion resistant coatings

In this study, ZnO/CuO hybrid hydrophobic nanopowders were synthesized using a common single-step chemical precipitation route without using modifiers. Influence of initial ZnO:CuO precursor concentrations and alkaline agent type on the wettability behavior of the prepared samples were investigated. Wettability properties of the prepared samples were assessed by measuring the water contact angle and contact angle hysteresis values. Fourier transform infrared spectra, scanning electron microscope micrographs and X-ray diffraction patterns were applied to identify the surface chemistry and morphological features. Scanning electron microscope images of the synthesized ZnO/CuO nanocomposites indicated flower-like morphologies containing plenty of nanoneedles, -rods, and -sheets with thicknesses lower than 90 nm. The sample prepared under the optimum conditions was superhydrophobic having water contact angle and contact angle hysteresis of 162.6 degrees +/- 1 and 2 degrees, respectively. It was applied to coat the surface of stainless steel meshes by spray deposition method. The resultant superhydrophobic surface exhibited excellent self-cleaning (water repellency) property and a suitable stabilities under the ambient and saline solution (NaCl, 3.5%) media. Additionally, electrochemical corrosion tests confirmed that the corrosion resistance of the fabricated ZnO-CuO coating was higher than the initial bare mesh.