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The abundant waste polyurethane sponge, commonly considered as one of the municipal wastes, can be recycled and converted into the valuable resources of environment. The increasing landfill cost and air-pollutions have made it a great urgent to develop the effective applications of waste polyurethane sponge. Recently, solar vapor generation has attracted extensive attentions, since energy shortage and water scarcity along with water pollution are becoming alarming global issues to be addressed. The solar vapor generation relies on the performance of the solar absorbers which convert the solar energy into heat for the vaporization process. A low cost, efficient and durable solar absorber is vital for the development of solar vapor generation. Here, we report that the recycled self-floating black polyurethane sponges are very promising solar absorber materials. which can efficiently generate water vapor after a simple one-step hydrophilic treatment with dopamine hydrochloride. The evaporating rate was more than 3.5 times higher compared to that of the existing natural evaporation process, exhibiting an evaporation efficiency of above 50%. Furthermore, this black polyurethane sponge can also drive solar ethanol distillation, yielding up to 25 wt% concentration promotion under each distillation cycle. [ABSTRACT FROM AUTHOR]

Efficient solar-enabled evaporation plays a critical role in solar power-based concentration systems, photochemical plants, seawater desalination technologies, etc. However, traditional processes for solar steam generation usually depend on high-temperature heating of the bulk liquid, which requires highly concentrated solar power and suffers from high energy and optical losses. Therefore, the enhancement of solar steam generation by bio-inspired interface solar heating is proposed in this work. In this study, easy-to-prepare, flexible, and reusable plasmonic membranes (PMs) were fabricated for realizing the bio-inspired interface solar heating and continuous steam transportation through the micropores of the membranes. A solar steam generation efficiency of ∼85% was achieved at an illumination power of 10 kW m −2 . The effects of Au concentration in the membranes and optical power on the steam generation efficiency were systemically studied. The observed high evaporation rate and efficiency were attributed to three main factors: high (∼90%) and broadband solar absorption, efficient photo-thermal conversion due to high plasmon dissipation losses, and fast capillary flow in the membrane micropores. Finally, the application of PMs in a single basin solar still system for seawater desalination was investigated and the PMs exhibited great performance on enhancing the productivity of clean water. [ABSTRACT FROM AUTHOR]

• Modeling framework of thermally-localized multistage solar stills (TMSS) is developed. • Heat and mass transfer in the TMSS are analyzed in detail. • Optimization strategies for the TMSS are presented. • Ultrahigh solar-thermal cumulative efficiency over 700% is predicted. Seawater desalination is a promising solution to global water shortage. Commercially available desalination technologies typically require large installations which can be impractical for developing regions without well-developed infrastructure. Passive solar desalination promises a viable solution, but can suffer from low efficiencies. Recent advances in the thermal design of small-scale solar desalination systems have demonstrated the potential for high-efficiency solar desalination in portable systems. In particular, the concept of a thermally-localized multistage solar still (TMSS) – which combines localized heating of a capillary flow with condensation heat recycling – has been experimentally demonstrated very recently and achieved over 100% solar-thermal cumulative efficiency. However, a fundamental understanding of the heat and mass transfer, efficiency limits and optimization strategies are missing in the literature. This work presents a modeling framework that evaluates the thermal and vapor transport in a model TMSS system with varying device configuration and predicts its solar desalination efficiency. We demonstrate that an ultrahigh solar-thermal cumulative efficiency, many times higher than that of conventional solar stills, can be achieved by optimizing the number of stages and device geometry. Specifically, our modeling shows that the efficiency of the capillary fed TMSS is limited by the dissipation of thermal energy to the environment during condensation and significant gains in efficiency can be achieved by minimizing this loss. This work provides insights into physical processes critical for thermally-localized portable solar distillation which could lead to high-performance desalination or water purification technologies. [ABSTRACT FROM AUTHOR]