RESUMEN

Natural solar-powered steam generation provides a promising strategy to deal with deteriorating water resources. However, the practical applications of this strategy are limited by the tedious manufacturing of structures at micro-nano levels to concentrate heat and transport water to heat-localized regions. Herein, this work reports the fabrication of hierarchically porous aerohydrogel with enhanced light absorption and thermal localization at the air-solid interface. This aerohydrogel steam generator is fabricated by a simple yet controllable micropore generation approach to assemble air and hydrogel into hierarchically porous gas-solid hybrids. The tunable micropore size in a wide range from 99±49µm to 316±58µm not only enables contrasting sunlight absorptance (0.2 - 2.5µm) by reducing the reflection of solar light but also harnesses water transportation to the heating region via a capillary force-driven liquid flow. Therefore, a solar-vapor conversion efficiency of 91.3% under one sun irradiation was achieved using this aerohydrogel evaporator, reaching a ready evaporation rate of 2.76kg m-2 h-1 and 3.71kg m-2 h-1 under one and two sun irradiations, respectively. Our work provides a versatile and scalable approach to engineering porous hydrogels for highly efficient steam generation and opens an avenue for other potential practical applications based on this aerohydrogel.

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RESUMEN

Given health threat by global warming and increased energy consumption in regulating body temperature, it is an urgent need to construct smart temperature-regulating materials. Herein, a novel fiber-spinning asymmetric chemical assembly (FACA) method is proposed to construct nanofiber materials with asymmetric photothermal properties. The silver nanowires (AgNWs) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) with opposite thermal radiation are assembled on reduced graphene oxide (rGO) film, imparting AgNW/rGO/PVDF-HFP film with Janus structure that can realize the AgNWs side consistently keeps temperature of ca. 11 °C lower than the side of PVDF-HFP nanofiber regardless of the irradiation directions under 1 sun, suggesting the adjustable photothermal regulation. Such photothermally selective hybrid nanofiber film provides great potential as fabrics to achieve all-weather smart clothes, promoting controllable and comprehensive utilization of solar energy.