A Chitin/CuS composite film for efficient solar seawater desalination

[Display omitted] •Chitin/CuS composite film was prepared.•Chitin/CuS showed sunlight induced photothermo performance.•Chitin/CuS film material demonstrated desalination efficiency over 99%. Solar-energy driven, fresh water production from seawater has been considered as a promising strategy to yield potable water. However this approach is typically expensive, energy intensive, as well as poorly yielding of clean water under natural sunlight. This has limited the practical application of solar-energy driven, fresh water production. Accordingly, we have investigated the development of new films with low cost and higher efficiency for solar desalination. We designed a hybrid film with a high desalination efficiency of over 99 % and the maximum desalination capacity of 10 kg/m2/h under simulated sunlight. The hybrid film was composed of a hydrophilic polymer framework (chitin) and a solar absorber (CuS) with an abundant porous structure for internal channel transportation. Chitin can greatly promote water evaporation in the hydrogel network, whilst the presence of CuS in the network facilitates efficient light-to-heat conversion. The internal channels of the chitin composite maintain a sufficient water supply for continuous solar vapor generation. Such hybrid films also have the advantages of excellent strength, high elasticity, as well as high cycling rates.