<i>Populus</i> -Inspired Aerogel Evaporator Based on Vertically Oriented Porous Structure for Efficient Solar Steam Generation

Solar steam generation is widely recognized as a sustainable and cost-effective technology for seawater desalination and wastewater purification, offering an efficient solution to mitigate global water scarcity. Herein, a <i>populus</i>-inspired aerogel evaporator composed of hydrophilic poly(vinyl alcohol) (PVA) and carbonized straw was fabricated through a directional freezing strategy. The incorporation of carbonized straw significantly enhanced the solar absorption of the evaporator to 95.1% while effectively reducing the material cost. Notably, the custom-designed vertically aligned channels in the evaporator significantly reduce water transport resistance, thereby enabling more rapid and efficient water delivery. Benefiting from its precisely tailored structure, the aerogel evaporator achieves a water evaporation rate of up to 2.6 kg m^-2 h^-1 and a solar energy conversion efficiency as high as 98.2% under 1-sun illumination (1 kW m^-2). Moreover, the evaporator exhibits excellent cycle stability and high practical applicability. This work presents a promising and practical strategy for fabricating highly efficient, eco-friendly, and cost-effective aerogel evaporators, demonstrating significant potential for real-world applications in seawater desalination and wastewater treatment.