Photocatalytic activity of oxide systems based on doped d-elements of titanium alloys
| Autor: | Mykola Sakhnenko, Iryna Stepanova, Svitlana Zyubanova, Anatoly Djenyuk, Sergey Indykov |
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| Rok vydání: | 2021 |
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| Zdroj: | Bulletin of the National Technical University «KhPI» Series: New solutions in modern technologies. :97-102 |
| ISSN: | 2413-4295 2079-5459 |
| Popis: | CO-, W-, MO- and Zn-containing hetero-oxide nanostructured coatings on titanium and its alloys formed by plasma-electrolyte oxidation in galvanostatic mode from alkaline electrolytes were investigated. The morphology of the surface of the formed coatings was studied by scanning microscopy on the Zeiss Evo 40XVP microscope. The phase composition of the obtained coatings was determined on the X-ray diffractometer Drone-2. Photocatalytic activity of ZnO-WO3/TiO2 films, ZnO-MOO3/TIO2, ZnO-Co3O4/TiO2, CoO-WO3/TiO2 tested in a model reaction of decomposition of an aqueous solution of azobye with a concentration of 12,2·10-5 mol/L (MО) at UV irradiation. It is shown that with plasma-electrolyte oxidation of titanium and its alloys in alkaline diphosphate electrolytes in the mode of «drop-down power» forming heterostructural composites with micro-globular surface morphology. The possibility of controlling the phase and elemental composition of oxide layers, as well as the topography of the surface by changing the composition of the electrolyte and the content of individual components, as well as the modes of formation is confirmed. Heteroxide coatings formed in PEO modes differ in composition and surface morphology, but all exhibit photocatalytic properties of varying degrees of activity. The study of the photocatalytic activity of the obtained coatings in the azo dye decomposition reaction by means of UV testing allowed to rank the heteroxide systems according to the specified parameter. Thus, the degree of decomposition of MF on ZnO-WO3/TiO2 films in 50 minutes was 23 %. Metal oxide systems ZnO-Co3O4/TiO2 had similar characteristics of the degree of decomposition – 21 %. The incorporation of CoO and WO3 oxides into the coating composition reduced the catalytic activity of the system to 19 %. The unstable mode of formation of ZnO-MoO3/TiO2 oxides and the low speed of the process have affected the quality of the catalytic coating activity, reduced the degree of decomposition of MO to values of titanium monoxide Ti/TiO2 without dopants. Comparison of quantitative characteristics of the properties of the obtained coatings allowed to determine the effects of dopants, incorporated into metal oxide systems, on their photocatalytic activity. |
| Databáze: | OpenAIRE |
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