Molecularly Copper-Coordinated Cellulose Heterogeneous Wettability Surface Induced Efficient Fog Harvesting

The development of efficient fog-harvesting materials is of great significance for addressing freshwater scarcity. However, conventional materials with hydrophilic/hydrophobic regions frequently struggle with coordinating water droplet capture and transport, resulting in lower water collection efficiency. Herein, an integrated strategy based on the engineering of cellulose molecular modification for achieving high-performance fog harvesting is presented. The well-designed cellulose heterogeneous wettability surface (CWF-Cu), through the coordination of copper ions with nanofibrils and masking-assisted spray technique, significantly facilitates water capture and transport for fog harvesting. The copper ions are introduced into the cotton fabric, endowing it with high hydrophobicity (with a contact angle of approximately 130°) and polarity, which regulates wettability and increases potential nucleation sites. The as-prepared CWF-Cu fabric realizes a superior water collection rate (WCR) of 2672 mg·cm −2 ·h −1 , increasing by 70% compared with those of the conventional hydrophobic materials. Moreover, the CWF-Cu fabric demonstrates stable performance to withstand the impact of water and pollutant flushing, and enhanced mechanical strength and ultraviolet (UV) durability, which ensures the long-term usability of the material. This work provides an efficient route to achieving efficient fog harvesting that addresses water scarcity from the environment.