Bilayer fiber membrane electrospun from MOF derived Co3S4 and PAN for solar steam generation induced sea water desalination

Solar steam generation system has attracted great attention because of high efficiency and low energy consumption in sea water desalination. Bilayer membrane is an important part in high efficiency solar steam generation system, which is built by thermal conversion and water transportation layers. With two-dimensional Co based Metal-Organic Framework (MOF) as precursor, Co3S4 hollow nanoparticle is synthesized, which exhibits excellent photothermal effect. With electrospinning technology, Co3S4 hollow nanoparticle and polyacrylonitrile (PAN) are weaved together and generates a bilayer membrane. Under one sun (1 ​kW ​m−2) irradiation, its evaporation rate reaches 1.26 ​kg ​m−2 ​h−1 with efficiency 86.5%. After 15 cycle continuous test, the performance of bilayer membrane is still well kept. The concentrations of Na+, K+, Ca2+ and Mg2+ in obtained water meet drinking standard. Co3S4 hollow nanoparticle can also be used as an activator to peroxymonosulfate (PMS) for tetracycline degradation with advanced oxidation processes (AOPs). Under catalysis of Co3S4 hollow nanoparticle, degradation rate of tetracycline (20 ​mg ​L−1, 30 ​mL) achieves 93.7% in 20 ​min. This donates potential application of this bilayer membrane in PMS involved tetracycline degradation. We can expect the promising prospect of bilayer membrane in sea water desalination and organic pollutants such as antibiotics removal.