Фотовідновлення токсичних іонів Cr(VI) у водному середовищі плівками ТіО2, допованими іонами вольфраму та активованими плазмовим опроміненням

• Datum: 2025
• Hauptverfasser: Petrik, І.S., Eremenko, A.M., Smirnova, N.P., Oranska, O.I., Frolova, E.K., Khomych, V.O., Kolomys, O.F.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2025
• Schlagworte: анатаз; рутил; вольфрам; фотовідновлення Cr(VI); опромінення; плазма
• Online Zugang: https://www.cpts.com.ua/index.php/cpts/article/view/831
• Назва журналу: Chemistry, Physics and Technology of Surface

Films of nanosized titanium dioxide doped with 0.1–10 mol. % of tungsten ions (hereinafter referred to in the text as W/TiO2) using titanium tetraisopropoxide Ti(OiPr)4 and (NH4)10W12O41·nH2O were obtained by the sol-gel method using non-ionic amphiphilic triblock copolymer Pluronic (P123) as a templating agent. The samples were investigated by XRD, Raman, UV-Vis and FTIR spectroscopy. W/TiO2 dispersions with the same chemical composition have been prepared via gelation of the solution of films precursors, after their drying at room temperature and calcination at 500 °C. Crystalline anatase phase was registered in XRD and Raman spectra of W/TiO2 films up to 10 % tungsten content with a minimum disturbance of the anatase-type structure. XRD patterns of W/TiO2 powders showed anatase (20–25 nm) and rutile (35–40 nm) nanocrystalline phases. The formation of tungsten oxide phases was fixed at its 10 % content. The photocatalytic activity of the films was examined in the photoreduction reaction of Cr(VI) ions to Cr3+ under UV irradiation in the presence of Na2EDTA as an electron donor. Films doped with 5–7 mol. % tungsten ions have higher photocatalytic activity compared to non-doped ones and demonstrated stable activity during                8–10 cycles. The addition of tungsten ions to titania matrix significantly improved its photocatalytic behavior. Tungsten ions doping promotes efficiency of the charge pair separation by trapping of photogenerated electrons with W5+ formation and preventing the charge recombination. When the dopant concentration was increased to 10 %, the photocatalytic efficiency a little decreased. To increase the photocatalytic activity of the coatings, the bare TiO2 and W/TiO2 samples were irradiated in a plasma mixture of hydrogen and argon (1 : 1). The efficiency of undoped TiO2 films has been increased 16 times, and W/TiO2 only by 2 times as the results of tungsten ions affecting the recombination processes.