Solar steam generation based on photothermal effect: From designs to applications, and beyond

To use broadband solar energy for producing clean water can potentially and effectively solve water pollution and shortage crisis. With rapid development of material science and nanotechnology, solar steam generation (SSG) based on photothermal nanomaterials is expanding by leaps and bounds. This review comprehensively covers the state-of-art designs and applications of SSG. In this review, photothermal effect, water supply, and thermal management are proposed as the three keys for the high-efficiency SSG system. Various kinds of photothermal materials with strong optical absorption covering the broad solar spectrum are classified and discussed with examples. Rational design of water supply and steam escape system enabling the SSG to proceed smoothly is reviewed. Current efforts to minimize the heat loss by a rational thermal management are also presented. As following, typical applications, such as desalination of seawater, purification of wastewater, photothermal steam sterilization, as well as related applications including light-driven thermoelectric system and photo-heat-catalyst are overviewed. At the end of this review, the remaining challenges to overcome, as well as opportunities to be seized are raised for open efforts.