Plasma-modified TiO2/polyetherimide nanocomposite fibers for photocatalytic degradation of organic compounds

For the first time, submicrometric polyetherimide (PEI) fibers were electrospun with incorporated TiO2 nanoparticles. Moreover, the fibers were submitted to cold plasma in air and nitrogen atmospheres to enhance adhesion and photocatalytic performance. The nanocomposites were characterized by scanning and transmission electron microscopy, X-ray diffractometry, UV-vis diffuse reflectance spectroscopy, contact angle, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. PEI-TiO2 nanocomposite fiber diameter was 691 +/- 416 nm (d(50)) with TiO2 nanoparticles of (similar to)30 nm particle diameter. Nanocomposite fibers exhibited a band gap of 3.55 eV and high hydrophilic behavior. The results suggest that the plasma treatment modified the interface between TiO2 nanoparticles and the PEI substrate but did not change expressively the anatase fraction of incorporated nanoparticles. After exposure to plasma-modified TiO2/PEI nanocomposite fibers, concerning photocatalysis, a total discoloration of methylene blue was achieved after 40 min; as well as 75% of methyl orange and tetracycline (TC) after 120 min. Moreover, the immobilized photocatalyst presented high stability after 5 successive cycles. Plasma-treated nanocomposite fibers reached kinetic constants up to 0.10 min(-1), 3 times higher than the values found in the literature.