A simple and universal strategy to deposit Ag/polypyrrole on various substrates for enhanced interfacial solar evaporation and antibacterial activity

Solar-driven distillation is now considered as a rising technology for the supply of fresh water in the rare areas. As the crucial part of solar distillation, photothermal materials have been flourished investigated. Herein, we report a universal and facile method to construct a photothermal layer on various substrates to enhance the interfacial water evaporation via polypyrrole (PPy) polymerization and silver nanoparticles (Ag NPs) deposition. The photothermal Ag/PPy layer was firmly coated on six different substrates with an average solar absorption of 95.4% and Ag loading of 94.3 mg/L. One of the optimized resultant membranes (substrate is cellulose fibers) presents the ultrahigh solar evaporation rate of 1.55 kg m⁻²h⁻¹ and a corresponding light-to-vapor efficiency of 92.6% with a silver loading of 74 μg cm⁻². Bacterial diffusion inhibition zone experiments revealed clear antibacterial effects of the Ag/PPy membrane on bacteria. Furthermore, the Ag NPs deposited membrane had a rechargeability for multiple times upon their depletion, indicating sustainable anti-bacteria potential. Hence, our facial fabricated photothermal Ag/PPy layer can apply to substrates with different types for enhanced photothermal and anti-biocorrosion capacity, and may pave a new way to the long-term practical sustainable technique for the clean water production application.