Interfacial Solar Steam Generation Enables Fast-Responsive, Energy-Efficient, and Low-Cost Off-Grid Sterilization.

Steam sterilization is widely used as one of the most reliable sterilization methods for public health. However, traditional steam sterilization mainly relies on electricity, a constrained resource for many developing countries and areas. The lack of available and affordable sterilization techniques in these areas is exposing human beings to a high risk of various epidemic diseases, and calls for the development of off-grid sterilization solutions. For the first time, the kinetic advantages of interfacial solar steam generation is fundamentally revealed and it is demonstrated that interfacial solar steam generation can enable fast-responsive (as short as 8.4 min for a full sterilization cycle) and energy-efficient (100 J mL for steam reaching 121 °C) sterilization, superior to those of the conventional sterilization techniques. The key solar absorber is made of low cost and widely available biochar. A proof-of-concept sterilization system with a 10.5 L solar autoclave is built with very low cost of whole life-cycle and operates with minimum carbon footprint. Effective sterilization (≈99.999999% inactivation of pathogen), exceeding the requirements of Food and Drug Administration is demonstrated, making the sterilization strategy a promising and complementary personalized sterilization solution, particularly beneficial for off-grid areas.