Hierarchically porous micro/nanostructured copper surfaces with enhanced antireflection and hydrophobicity

A facile hydrothermal method has been proposed to fabricate hierarchically porous Cu micro/nanostructures on Cu foil, whose growth can be controlled by the reaction time and the amount of ethylene glycol added into the precursor. Compared to commercially available Cu foil, the micro/nanostructured Cu surfaces exhibit not only greatly enhanced ability to absorb light over a wide range of wavelengths from 250 to 1000 nm, but also improved hydrophobicity from 90.4 degrees to 151.2 degrees without any low-surface-energy chemical modification. The reflectance can reach a lowest value of 10% at 300 nm and show a biggest decrement of 53% at 582 nm. Due to their superhydrophobicity, the micro/nanostructured Cu foils demonstrate an improved anticorrosion ability against 3.5 wt% NaCl solution compared with a bare one. The proposed mechanism indicates that the combination of the dual-scale roughness and the adsorbed air in pores account for the enhanced antireflection and hydrophobicity. (C) 2015 Elsevier B.V. All rights reserved.