Fabrication of Superhydrophobic Hierarchical Surfaces by Square Pulse Electrodeposition: Copper-Based Layers on...

Copper based layers were fabricated on gold/silicon (100) substrates by using square pulse electrodeposition at different deposition temperatures. The predominant crystalline plane on Cu₂ O samples at temperatures higher than 30 °C is (111), which is the most hydrophobic facet of Cu₂ O cubic structure. Different crystallite structures such as semivertical leaves, fractal trees, and octahedral pyramids were formed on the surface. These water-repellent samples have hierarchical structures, including octahedral pyramid microstructures with small spherical balls on them and well-branched micrometric vertical leaves on the surface. They provide a suitable surface for trapping air pockets inside the structure and increasing the water contact angle up to 154°. This approach may be applicable to the large-scale preparation of water-repellent surfaces as superhydrophobicity can be achieved in a one-step deposition process without any secondary modifications.