One-step facile fabrication of PDA@MCE for high efficiency seawater desalination.

• The photothermal film with Janus structure was prepared by one step method. • The photothermal film can realize self-floating and avoid salt accumulation. • Polydopamine has excellent adhesion and stability to mixed cellulose membrane. A variety of photothermal materials have been developed and applied in photothermal seawater desalination. As a conjugated polymer, Polydopamine (PDA) has excellent light absorption properties in the UV–visible region, and is widely used as a solar energy material. In this work, Polydopamine-mixed cellulose membrane (PDA@MCE) with Janus structure was prepared by a one-step method for water evaporation at the interface between PDA and mixed cellulose membrane (MCE). PDA@MCE has good thermal stability. When the reaction time is 6 h, the evaporation rate of the composite is twice that of MCE, and the photothermal conversion efficiency is about 62 %. PDA@MCE, as a kind of photothermal material with simple preparation method and friendly to the environment, has excellent application potential in solar driven interfacial water evaporation. [ABSTRACT FROM AUTHOR]