Naslov
Synthesis and characterization of ZnO nanodots and nanorods for photocatalytic degradation of organic pollutants

Autori
Podlogar, Matejka ; Seleš, Patrick ; Kocijan, Martina ; Radošević, Tina ; Shvalya, Vasyl ; Vengust, Damjan ; Bernik, Slavko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
57th International Conference on Microelectronics, Devices and Materials & The Workshop on Energy Harvesting: Materials and Applications, conference 2022: proceedings / Rojac, Tadej ; Otoničar, Mojca - Ljubljana : Society for Microelectronics, Electronic Components and Materials (MIDEM), 2022, 123-124

ISBN
978-961-95495-1-3

Skup
57th International Conference on Microelectronics, Devices and Materials & The Workshop on Energy Harvesting: Materials and Applications

Mjesto i datum
Maribor, Slovenija, 14.09.2022. - 16.09.2022

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
solvothermal , ZnO, nanorods, nanodots, caffeine, molybdenum blue, degradation

Sažetak
Nano zinc oxide (ZnO) gained a lot of attention for photocatalytic applications and is frequently used to degrade many organic pollutants in water, from dyes to microplastics. Photocatalysis, is a chemical oxidation processes, where commonly nanostructured semiconductor (photocatalyst) is irradiated with an appropriate light energy to create electronhole pairs, that react with the surrounding water and produce superoxide and hydroxyl radical that can oxidize given chemical species/pollutant. As photocatalysis is an exclusively surface driven process, its activity depends on the particle size, specific surface area and morphology of the used photocatalyst. Nanostructured materials with high surface to volume ratio have high photocatalytic degradation efficiency. In our study, ZnO nanodots was prepared by sol-gel technique, and additional solvothermal treatment, in autoclave at 150 or 200°C for 24 or 120 hours, transformed nanodots to nanorods. Synthesized nanopowders were characterized using X-ray diffraction analysis (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocatalytic activity of prepared ZnO nanostructures was investigated by caffeine and molybdenum blue degradation. The photocatalytic degradation was carried out in cylindrical reactor with quartz cover, where 5 mg of photocatalyst was added to 5 mL of pollutant solution. Before irradiation, samples were kept in the dark for 60 min to reach the adsorption desorption equilibrium. Suspensions of ZnO in pollutant solution were irradiated under stirring using a UV-vis simulated sun spectrum (Ultra Vitalux, 300 W, Osram). At pre-defined time intervals, the caffeine/MB concentration was analyzed by spectrophotometer (Lambda 950 UV/Vis/NIR, PerkinElmer). We correlate the obtained degradation rate with the crystallinity, crystal size, aspect ratio, specific surface area and structural and surface defects. Nanorods solvothermally synthesized at 200 °C for 24 h showed the highest photocatalytic activity, and consequently we tested them also for photocatalytic degradation of synthetic microfibers (PET, PA). SEM and Raman analysis, after the exposure by simulated sun light irradiation, showed changes on surface of plastic fibers.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Kemijsko inženjerstvo, Temeljne tehničke znanosti

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