Fabrication of biomimetic laser etched superwetting copper surfaces for highly improved mist collection efficiency

Water scarcity has become a serious global issue due to frequent global climate extremes such as warming, storms, floods and droughts. Developing highly efficient water-harvesting materials to collect freshwater from mist is a potential solution to solving the issue. Herein, a series of superwetting copper materials with excellent mist collecting efficiencies were successfully prepared via facile etching, modification, laser-scanning and plating methods. The sample surfaces showed unique wettability and structure characteristics that numbers of hydrophilic humps were regularly arrayed and embed into the superhydrophobic surface with nanorod structures. The surface structure, chemical composition of the superwetting copper materials were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. Excellent mist collection efficiency of the fabricated superwetting copper materials was verified by mist collection tests. In addition, the enhancing mechanism of mist collecting behavior on the superwetting copper surface was analyzed. The excellent mist collecting performance of the prepared surfaces exhibited promising potential to achieve mist collecting materials.