Efficient evaporation of seawater desalination by novel double-interface evaporator: Photothermal conversion, water transfer and salt-resistant

Interfacial solar-driven water evaporation emerged as an established eco-friendly method for seawater desalination to combat water scarcity, yet the low water evaporation rate and cost-effectiveness limit the practicable application. Herein, we presented a double-interface evaporator with a bilayer structure (BCCu@FC). C u @FC). The upper layer was constructed using carbonized copper-doped biochar (BCCu), C u ), which exhibited broadband sunlight absorption and effective photothermal conversion capability for the localized surface plasmon resonance (LSPR) effect. Meanwhile, the lower layer was constructed by felt fabric (FC), which featured a large spatial network structure, guaranteeing sufficient water transportation. Therefore, BCCu@FC C u @FC exhibited a high photothermal conversion efficiency of 87.05% with a 1.571 kg m-2 h-1 water evaporation rate under 1 sun illumination. Moreover, BCCu@FC C u @FC further exhibited high stability and salt resistance, showing no significant salt crust formation after continuous operation for 24 h under 3.5 wt% brine. Especially, BCCu@FC C u @FC could stably work under 21 wt% brine, and the salt crust re-dissolved within 4 h after the cessation of illumination. This facile and universal strategy was anticipated to pave the way for future designs and fabrication of diverse, more efficient, and cost-effective photothermal conversion devices.