Biomimetic design of solar evaporator based on biodegradable, low-cost and eco-friendly composite aerogel for efficient solar steam generation

Solar-driven interfacial evaporation technology has been widely recognized as an effective way to alleviate the global water scarcity issue. Despite significant progress in achieving high energy conversion efficiency, the lack of low-cost, stability and environmental friendless severely limits its practical applications. Herein, we report a jellyfish-inspired solar evaporator that consists of a microcrystalline cellulose/carbonized corn straw composite aerogel (MCCA) photothermal layer serving as the jellyfish bell to achieve high solar absorption (95.5 %), sufficient water supply, rapid vapor release and excellent thermal insulation, as well as the cotton slivers acting as the jellyfish tentacles for stable water pumping to the jellyfish bell. The solar evaporator demonstrated a high water evaporation rate of 1.62 kg m- 2 h- 1 and corresponding solar energy conversion efficiency of 96.34 % under 1 kW m- 2 (1-sun) illumination. Notably, the fabrication of the evaporator is environmentally friendly as the utilization of straw effectively alleviates the air pollution caused by open burning while the microcrystalline cellulose is biodegradable. Anyway, the developed technique offers significant potential for practical applications in seawater desalination and wastewater purification due to its low-cost, environmental friendless, cycling stability and abundant raw materials.