An alternating nanoscale (hydrophilic–hydrophobic)/hydrophilic Janus cooperative copper mesh fabricated by a simple liquidus modification for efficient fog harvesting

The cooperation of different fog harvesting mechanisms together is now a hot topic, which can improve the efficiency of fog harvesting. Apart from an efficient harvesting mechanism, easy and low-cost fabrication of a fog collector is also key to accessing fresh water for usage. Herein, for the first time, we endowed a copper mesh with bio-inspired nanoscale alternating hydrophobic–hydrophilic chemistry patterns and Janus asymmetric wettability at the same time by a one-step simple liquidus modification. This method presents new insights for the fabrication of surfaces with special wettability. The nanoscale hydrophilic–hydrophobic/hydrophilic Janus copper mesh can use different harvesting mechanisms together and achieve efficient fog harvesting. Compared with the corresponding superhydrophilic membranes, the Janus membrane showed an ∼800% fog harvesting enhancement.