Photocatalytic optical fibers with ZnO:Sn,Fe coatings for localized reactive oxygen species generation
Egor P. Bykov1, Larisa L. Khomutinnikova1, Kirill V. Babaev1; 1ITMO University, St. Petersburg, Russia
Abstract
Localized generation of reactive oxygen species on optical fibers is a promising approach for compact photochemical systems, including minimally invasive disinfection and targeted photooxidative treatment. In this work, ZnO:Sn,Fe-based photocatalytic fiber systems were developed using direct formation of an oxide layer on SMF-28 silica optical fibers by a polymer-salt method and low-temperature preparation of ZnO:Sn,Fe-loaded medical silicone coatings.
As for the direct formation method, the protective acrylate coating was removed from the fiber, followed by dip-coating with a polymer-salt precursor and thermal treatment at 550 °C. X-ray diffraction confirmed the formation of crystalline ZnO with a wurtzite structure, while scanning electron microscopy demonstrated a dispersed layer of oxide agglomerates distributed over the cylindrical fiber surface. Singlet oxygen generation was evaluated by electron paramagnetic resonance using 2,2,6,6-tetramethylpiperidine as a spin-trapping agent. Under 365 nm irradiation, linear accumulation of the TEMPO radical was observed, with a generation rate of 0.30 µM min-1. The coating increased the methylene blue photodegradation rate by a factor of three compared with photolysis (0.012 vs. 0.004 min-1).
The low-temperature method involved mixing ZnO:Sn,Fe powder with medical silicone. Methylene blue photobleaching was used to optimize the powder loading in silicone films and to verify the selected ZnO:Sn,Fe/silicone ratio. Silicone-based samples with a mass of 150 mg and dimensions of 30x10x0.3 mm showed photoinduced dye bleaching under 365 nm irradiation, indicating that the photocatalytic powder retained photooxidative activity in the silicone matrix.
Speaker
Egor Bykov
ITMO University
Russia
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