A flexible and highly efficient graphene-based photothermal evaporation device with independent water transport and photothermal absorption system

Solar interfacial evaporation is a new desalination technology, which has the advantages of low cost, low energy consumption, simple system and no pollution. New material development is crucial to improving the light absorption ability, photothermal conversion efficiency, and water evaporation. In this study, a separate photothermal evaporation device is proposed. The graphene oxide (GO) was combined with polyacrylonitrile (PAN) to form a composite (GO/PAN) fiber by wet spinning. GO/PAN fiber as a photothermal absorption system was further woven with cotton yarn to produce a flexible photothermal conversion device. When the device is put in fuchsin solution, it can absorb water within 20 s and be completely soaked in the solution after 25 s. When the device was irradiated by 1 standard sunlight, the water evaporation rate was 1.82 kg m−2 h−1. Under 5 or 10 standard sunlight, the water evaporation rate could reach 5.19 kg m−2 h−1 and 11.79 kg m−2 h−1, respectively. The graphene photothermal evaporation device of the invention adopts the method of interfacial evaporation here is easy to manufacture and has good flexibility. With the help of independent water transport and photothermal absorption system, the device can achieve high water absorption and photothermal properties, showing great potential for high-efficiency water desalination.