Résumé
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•Composite nanofibers were synthesized using Electrospinning and ALD.•A degradation of 90.8 % of acetaminophen was achieved after 4 h under visible light.•A decrease in degradation efficiency of 25 % was observed after five cycles.•Acute toxicity and scavenging tests highlighted the significant roles of O2−, and h+ species in acetaminophen degradation.•DFT calculations demonstrate charge transfer processes that improve the photocatalytic efficiency of NiO-TiO2.
Light-driven water treatment methods have garnered significant attention for their ability to effectively degrade harmful pollutants. In this study, polyvinylpyrrolidone (PVP)-based titanium dioxide nanofibers were synthesized using a sol–gel method combined with electrospinning, followed by calcination at 500 °C. Nickel oxide (NiO) layers of 5, 10, and 20 nm thickness were subsequently deposited onto the nanofibers via atomic layer deposition (ALD) using bis(ethylcyclopentadienyl)nickel and ozone as chemical precursors. The structural and functional properties of the fibers were characterized using electron microscopy, surface area analysis, and various spectroscopic techniques. The incorporation of NiO into TiO2 nanofibers enhanced light absorption, suppressed charge recombination, and improved photocatalytic performance under visible light, as confirmed by reflectance and photoluminescence spectra. Photocatalytic tests demonstrated that fibers with 5 nm NiO exhibited superior performance, achieving 91 % degradation of acetaminophen under visible light within 4 h, compared to 70 % for bare TiO2. Moreover, the 5 nm NiO-coated fibers maintained their performance over five cycles, with a slight reduction of 28 %. Reactive species analysis revealed the involvement of hydroxyl and superoxide radicals in the degradation process. Density functional theory (DFT) calculations further elucidated that the enhanced photocatalytic efficiency of the NiO (5 nm)-TiO2 composite (denoted as N5T) stems from optimized electron-hole separation and improved photon energy retention. These findings highlight the potential of N5T nanofibers for water treatment applications and provide valuable insights for the development of advanced light-driven catalysts.