Salt-resistant, environment-friendly silk/melanin composite aerogel with directional channel for solar-driven evaporation

A salt-resistant solar-driven interface evaporator was prepared from silk fibroin with a directional channel structure, coated with natural black melanin for solar light harvest and photothermal conversion. This silk fibroin-melanin (SF-melanin) solar-driven evaporator achieved a water evaporation rate of up to 2.49 kg m-2 h-1 under 1 sun beneficial from the intrinsic hydrophilicity of silk fibroin, the directional channel structure, and the high efficiency of solar light harvest and photothermal conversion of natural black melanin. The directional channel structure also facilitates the rapid dissolution of salt crystals back to the native solution, enabling stable performance during the long-term solar-driven desalination process. Moreover, this SF-melanin solar-driven evaporator can totally be degraded in soil since all of its components are bioresource. This high efficient, salt-resistant, biodegradable solar-driven evaporator will further promote the practical application of solar-driven evaporator.