Improved Water Collection from Short-Term Fog on a Patterned Surface with Interconnected Microchannels

Abstract

Fog harvesting is considered a promising freshwater collection strategy for overcoming water scarcity, because of its environmental friendliness and strong sustainability. Typically, fogging occurs briefly at night and in the early morning in most arid and semiarid regions. However, studies on water collection from short-term fog are scarce. Herein, we developed a patterned surface with highly hydrophilic interconnected microchannels on a superhydrophobic surface to improve droplet convergence driven by the Young−Laplace pressure difference. With a rationally designed surface structure, the optimized water collection rate from mild fog could reach up to 67.31 g m −2 h −1 (6.731 mg cm −2 h −1 ) in 6 h; this value was over 130% higher than that observed on the pristine surface. The patterned surface with interconnected microchannels significantly shortened the startup time, which was counted from the fog contact to the first droplet falling from the fog-harvesting surface. The patterned surface was also facilely prepared via a controllable strategy combining laser ablation and chemical vapor deposition. The results obtained in outdoor environments indicate that the rationally designed surface has the potential for short-term fog harvesting. This work can be considered as a meaningful attempt to address the practical issues encountered in fog-harvesting research.

Improved Fog Collection on a Hybrid Surface with Acylated Cellulose Coating

“…The primary method of active water collection involves fog collection, known for its effectiveness, simplicity, and cost-efficiency, making it particularly suitable for addressing water scarcity in semiarid and water-deficient regions . In recent years, researchers have focused on improving the efficiency of fog collection to promote better practical applications. − Because of the efficiency of fog collection depending on the design and construction of the surface engineering, many studies have reported innovatively constructing superhydrophilic–superhydrophobic hybrid surfaces (SSHSs) on the metal surface to improve fog collection efficiency inspired by the desert beetle. For instance, Liu et al constructed a hydrophilic–superhydrophobic hybrid surface on stainless steel using chemical etching and mechanical hole drilling to enhance fog collection efficiency .…”