Bio-based interfacial solar steam generator

Solar steam generation (SSG) utilizes green, widespread solar energy as an energy source, making it a promising technology for seawater desalination and wastewater purification. Interfacial SSGs (ISSGs) localize the heat converted from solar energy at the air-water interface to enhance interfacial temperature and decrease heat loss to bulk water, leading to a significant increase of solar-to-vapor conversion efficiency. However, ISSGs still face significant limitations in fabrication cost, overall efficiency, and biodegradability. Bio-based ISSGs have attracted much attention for their sustainability and low cost. A large number of high-efficiency bio-based ISSGs have been developed in the past decade. Reviews on bio-based ISSGs are still rare. This review first introduces the state-of-art development of the key processes and general principles of ISSG devices, including energy sources, photothermal conversion, thermal management, water supply, evaporation enthalpy, and durability. All these processes are crucial to the final performance of ISSGs, requiring careful design and tuning to achieve high efficiency. Then a variety of bio-based ISSGs are elaborated upon, such as those made from wood, bamboo, lotus, rice, pomelo peel, sunflower, cuttlefish ink, mushroom, and algae. Bio-based ISSGs excel in sustainability and low cost but still suffer from low efficiency and short durability. The use of biological materials with water collection abilities is also discussed for designing water collectors. Finally, the challenges and promising prospects of bio-based ISSGs are discussed, including efficiency, extraction of bio-based materials, stability, durability, and condensation rates. This review aims to facilitate and inspire the rapid development of bio-based ISSGs.