under natural sunlight. After a micrometer-thick film of polyamide 11 nanofibers was deposited on polypropylene filter fabric, TiO2 NPs were directly electrosprayed onto the nanofibers.206 Scanning electron microscopy (Figure 7) demonstrated that nanofibers were uniformly coated by TiO2 NPs without agglomeration. TiO2-coated filters showed excellent photocatalytic and bactericidal activity and photoinduced hydrophilicity.
Figure 7  Scanning electron microscope images of electrospun nanofibers on polypropylene filter fabric (