Aluminum-Based Heterogeneous Surface for Efficient Solar Desalination and Fog Harvesting Processed by a Picosecond Laser

Abstract

Solar desalination and fog harvesting are two common ways to obtain fresh water, and both are promising methods to solve the water shortage problem. However, through either the fabrication of interfacial evaporators for solar desalination or the preparation of superwetting surfaces for fog harvesting, current methods suffer from long preparation times, high costs, and low efficiency. Herein, we report an efficient and simple method to process heterogeneous surfaces (HSs) on aluminum (Al) by picosecond laser processing combined with chemical treatment used for fog harvesting and seawater desalination. The as-prepared HS simultaneously consists of regular periodic stripe structures with superhydrophilicity and superhydrophobicity. The spacing of the superhydrophilic and superhydrophobic regions can be adjusted through the processing path. This surface has a 44% improvement in fog harvesting efficiency compared to a pristine Al sheet, which is 0.53 kg•m −2 •h −1 . Furthermore, it shows a high evaporation rate of 2.35 kg•m −2 •h −1 under one sun irradiation with an energy efficiency of 52.39%. Such functional surfaces can be applied to obtain fresh water resources in both coastal regions and arid areas, where water mist is relatively abundant, providing reference and guidance for fresh water collection, and being a promising way to solve the water shortage problem.

A porous micro/nano-structured polyethylene film prepared using a picosecond laser for agricultural passive cooling

“…29–34 Meanwhile, it can construct controllable three-dimensional microstructures on different substrates in a non-contact form. 35,36 In most cases, the laser beam forms microstructures on the substrate due to the thermal effect caused by the ablation of a high energy density laser. 37–40 These microstructures can enable material parts to have self-cleaning functions, as well as increase the reflectivity of several materials, reduce transmittance, and achieve passive cooling.…”

Improved Fog Collection on a Hybrid Surface with Acylated Cellulose Coating

“…In another study, Liang et al constructed an SSHS on the Al substrate for the efficient collection of fog by means of a picosecond laser and a chemical treatment. 28 The SSHS featured superhydrophilic/superhydrophobic periodic stripes, with the superhydrophilic stripe facilitating droplet capture and transportation through a liquid film, whereas the superhydrophobic stripe collected fog through adsorption. The fog collection efficiency was improved by 44% compared to the original Al sheet.…”