Multifunctional nanofiber membrane with antifouling properties for efficient seawater desalination and wastewater purification

Abstract

Solar-driven water evaporation has attracted widespread attention for its extensive applications in the production of clean water from seawater and wastewater. However, most of the designed evaporators focus on evaporation performance but ignore the antifouling ability, particularly the evaporator used for wastewater treatment. Herein, a cellulose acetate (CA)/polyaniline (PANI)/copper sulfide (CuS) nanofiber membrane with a core-shell structure was designed as an evaporator. The super-hydrophilic CA nanofiber membrane was obtained by deacetylation, which could provide sufficient water for water evaporation. Meanwhile, the in situ polymerization of PANI on CA nanofiber facilitates the growth of a uniform CuS layer on the fibers. Consequently, the synergistic effect between PANI and CuS not only improved the light absorption and photothermal conversion ability but also enhanced the photocatalytic ability of composite membranes. The d-CA/PANI/CuS evaporator exhibited a high evaporation rate of 1.45 kg m−2 h−1 under one solar radiation. Due to the excellent photocatalytic self-cleaning ability, the average evaporation rate of d-CA/PANI/CuS nanofiber membrane for methylene blue (MB) solution remained at 1.42 kg m−2 h−1 in a long-term evaporation experiment. This work may shine a new light on the design of novel antifouling evaporators with photocatalytic self-cleaning capability for seawater desalination and wastewater treatment.