In situ surface formation of TiO2/Ti(NO2) hybrid nanocomposites with N2 APPJ treatment for efficient C2H4 photodegradation.

TiO2/Ti(NO2) hybrid films were prepared using N2 atmospheric pressure plasma jet treatment on TiO2 coating. The film structure and morphology have been investigated using optical emission spectra, Fourier-transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The formed TiO2/Ti(NO2) photocatalystic thin films were applied for C2H4 photodegradation under UV irradiation. The results showed that the composite films exhibited superior photocatalytic activity over the untreated TiO2 film. The C2H4 concentration after 120 min varied from 12 to 6.2 mg/L, 6.7 mg/L, 7 mg/L for TiO2 with 1 min, 2 min and 3 min plasma treatment, respectively. In the banana storage experiment, the concentration of C2H4 was reduced from 15 to 9 ppm after 36 h with TiO2/Ti(NO2) nanocomposite film illuminated by UV light. The photocatalytic mechanism has been discussed. The composite film is able to more effectively separate the photo-excited electrons and holes, thus leading to the much high activity in C2H4 degradation. The current work has paved a way towards postharvest fruit preservation.

Immobilized Ag3PO4/GO on 3D nickel foam and its photocatalytic degradation of norfloxacin antibiotic under visible light.

In this study, a series of Ag3PO4/graphene oxide (GO) films were dip-coated on a metal nickel foam. The immobilized catalysts were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, Raman spectroscopy, high-resolution transmission electron microscopy and photoluminescence spectroscopy. The results show that Ag3PO4/GO was successfully supported on a nickel foam. The photocatalytic activity of the film catalyst under visible light was investigated by the degradation of norfloxacin, an antibiotic. Photocatalytic stability of this catalyst was also investigated. An optimized film exhibited superior activity and stability, the degradation rate of norfloxacin was about 83.68% in 100 min and the reaction rate constant k was 1.9 times that of pristine Ag3PO4. Further investigation found that photo-generated holes (h+) and superoxide anion radicals (·O2 -) are the main active species in the photodegradation process. The result indicates that the addition of GO inhibits the recombination of photogenerated electron-hole pairs, and thus has improved the photocatalytic activity and cyclic stability under visible light. The photocatalytic mechanism of the film catalyst was proposed. The prepared Ag3PO4/GO film catalyst is a promising candidate for treatment of wastewater containing antibiotics.