Bio-Derived Photothermal Materials and Evaporators for Sustainable Solar Energy-Driven Water Process

Interfacial solar steam generation (ISSG) is considered as an excellent seawater desalination technology because of its electricity-independent nature, low cost, and portability. However, improving the water evaporation efficiency, simplifying the fabrication process, and reducing the overall cost of the evaporator are still challenging. Here, an efficient and sustainable solar water evaporator is fabricated with carbonized ginkgo biloba leaves as the structural basis of photothermal materials. The combination of the abundant capillary channels in ginkgo leaves paired with polyacrylamide (PAM) hydrogel accelerates water transportation and solar-driven evaporation. The fabricated evaporator shows excellent photothermal conversion capability and evaporates water at 2.39 kg m–2 h–1 under 1 sun irradiation. In addition, the device exhibits remarkable stability in simulated seawater and can effectively realize seawater desalination or sewage treatment. As a result, the system is promising for future highly efficient solar evaporation due to its environmental protection and low cost.