Towards highly salt-rejecting solar interfacial evaporation: Photothermal materials selection, structural designs, and energy management

With the development of the industry, water pollution and shortage have become serious global problems. Owing to the abundance of seawater storage on earth, efficient solar-driven evaporation is a promising approach to relieve the freshwater shortage. The solar-driven evaporation has attracted tremendous attention due to its potential application in the seawater desalination and wastewater treatment fields. Also, the solar-driven evaporation efficiency can be enhanced by designing both solar absorbers and structures. Up to now, many strategies have been explored to achieve high solar-driven evaporation efficiency, mainly including the selection of photothermal conversion materials and structure optimization. In this review, the solar absorbers, structural designs, and energy management are proposed as the keys for high performance solar-driven evaporation systems. We report four kinds of solar absorbers based on different photothermal conversion mechanisms, substrate structure designs, and energy management methods for the purpose to achieve high conversion efficiency. And we also systematically investigate the available salt-rejections strategies for seawater desalination. This review aims to summarize the current development of efficient solar-driven evaporation systems and provide insights into the photothermal conversion materials, structural designs, and energy management. Finally, we propose the perspectives of the salt-rejection technologies for seawater desalination.