Bio-derived ultrathin membrane for solar driven water purification

Harvesting solar energy for water purification is an efficient and sustainable way to produce clean water. Herein, we demonstrate a bio-derived free-standing ultrathin membrane generated from daily bio waste of eggshell membrane, for the first time, to be utilized for solar driven water purification with ultrahigh energy efficiency. The combined characteristics of vapor-transportation-favorable morphology, enhanced broadband absorption, and heat-localization render the bio-derived membrane remarkable solar-driven water purification performance. Ultrahigh solar steam evaporation efficiency as well as membrane distillation-induced permeate flux under one sun illumination with outstanding salt and molecular rejection rate were reported. Screening and modification of bio-derived materials represent a cost-effective and environmental-friendly strategy for developing highly efficient water purification membranes.