Portable Trilayer Photothermal Structure for Hybrid Energy Harvesting and Synergic Water Purification.

Many exciting developments have unfolded on the recently emerged research topic of solar-driven interfacial evaporation, which is a promising technology for water purification. However, the sole heat source, i.e., solar energy, has put a limit on the maximum achievable evaporation rate. Therefore, to boost the evaporation beyond the limit, we here in this work have put forth a new photothermal system with a trilayered structure (TLS) that is capable of simultaneously harvesting hybrid energy in addition to solar energy for enhanced evaporation. A carbon-based material with broad-band light absorption that can be facilely synthesized through dehydration effect is also reported. Demonstrations of TLS evaporator by recovering the free thermal energy from sources like ground surficial heat and waste heat from laboratory facility and building walls together with solar radiation have been carried out. A remarkable synergic evaporation rate exceeding 2.4 kg m-2 h-1 is achieved, and moreover, the hybrid heating makes evaporation independent of solar intermittency. Besides, a TLS integrated hybrid water-purification bottle with outstanding portability is further demonstrated, which is expected to be of great significance to the development of mobile water purification and safe water security in the future.

A Barbeque-Analog Route to Carbonize Moldy Bread for Efficient Steam Generation.

Sustainable reconversion of the large quantities of food waste generated every day is pivotal for a green urban development in future. Herein, we put forth a sustainable and cost-effective way to repurpose a commonly used food waste for solar steam generation, an important part of water desalination. Making use of moldy bread, a new route for steam generation is demonstrated. The moldy bread was converted into a solar absorber by a simple and cost-effective carbonization process mimicking outdoor barbeque cooking. Carbonizing food waste to facilitate better absorption of sunlight for effective evaporation of water is an unprecedented concept in this field. Interestingly, the carbonized bread repurposed from the food waste served as an effective solar steam generator with an efficiency as high as 71.4% under 1 sun illumination. The structural and thermal absorption properties of the carbonized bread facilitated efficient solar energy absorption, heat management, and water transpiration in the system.