Mushroom-like double-layer aerogel with expanded evaporation area in limited space volume for solar interface evaporation applications

Solar-driven interfacial evaporation offers a promising solution to freshwater scarcity. However, the confined space restricts light absorption and evaporation area, thereby constraining its operational performance in desalination. In this study, a bilayer aerogel with a mushroom-shaped, umbrella-like structure was developed for desalination. The polypyrrole/polydopamine composite photothermal absorption layer enhances light absorption effectively with its textured surface, while the water transport layer of bacterial cellulose/acrylamide hydrogel provides consistent water delivery via capillary action. Experimental findings indicated that the aerogel attained an evaporation rate of 1.30 kg·m −2 ·h −1 and a solar-to-thermal conversion efficiency of 80.3%. Additionally, the evaporation efficiency was consistent throughout 35 successive testing cycles. The aerogel shows strong potential for application in solar-driven interfacial evaporation desalination. Download: Download high-res image (253KB) Download: Download full-size image