PC@PPy porous membrane prepared by breath figure method with superior mechanical property for efficient solar interfacial evaporation.

• A simple breath figure method was first employed to fabricate double-layer evaporator. • The PC@PPy has advantages of low cost, simple and scalable manufacture process. • The PC@PPy-EPE shows excellent energy conversion efficiency of 93.57% under 1 sun irradiation. • The PC@PPy-EPE displays excellent salt-resistant performance even in 20 wt% NaCl. Solar interfacial evaporation (SIE) is one of the most prospective solar energy harvesting technologies for solving the scarcity of freshwater resources. Herein, we report a novel photothermal membrane polycarbonate (PC)@polypyrrole (PPy) (PC@PPy) adopting to breath figure method followed by surface chemistry modification, and assemble a double-layer solar interfacial evaporator consisting of PC@PPy photothermal membrane as the upper layer and plant fiber-wrapped expanded polyethylene (EPE) foam as the bottom layer for SIE. Due to the abundant porous structure and strong light absorption of the PC@PPy membrane, excellent insulation of the EPE sponge, the as-prepared PC@PPy-EPE evaporator exhibits a high evaporation of 1.78 kg m-2h−1 and photothermal conversion efficiency of 93.57%, and outstanding evaporation stability and resistance in 16% wt NaCl with an evaporation of 1.58 kg m-2h−1 under 1 sun irradiation. Moreover, the PC@PPy photothermal possess superior flexibility and strong mechanical properties. Coupling with cost-effective, environment-friendly, simple and easily scale-up breath figure preparation method, the PC@PPy-EPE generator has broad application prospects in SIE. [ABSTRACT FROM AUTHOR]