NEW ZINC OXIDE PHOTOCATALYTIC THIN FILMS PREPARED BY DIP-COATING TECHNIQUE AND APPLICATION FOR DYE-DEGRADATION
autorzy: Le Minh Kiet, Duong Quoc Minh, Pham Thuc Hien, Pham Ngoc Thuy Linh
In this study, Sn-doped zinc oxide (ZnO) thin films were first deposited on several substrates at 550°C by a dip-coating technique using the solution synthesized by the sol-gel method. The structural, surface morphology, optical and photocatalytic properties of the thin films were studied with TGA, X-ray diffraction (XRD), and SEM. The Sn doped thin films accelerated MB degradation better than ZnO in order of SZO4% > SZO2% > ZnO. After 105 mins SZO4% thin-film degraded 97.9% MB in the aqueous solution, while 84.9% and 70.2% amount of MB were degraded when using SZO2% and ZnO, respectively. Kinetically, the MB degradation was followed the first-order equation. Interestingly, after 5 times, the photocatalytic ability of these ZnO, SZO2%, SZO4% was decreased insignificantly. Totally, after 5 times of use, 1.0 g of SZO4% thin film can degrade 190mg of MB. The degradation of MB was monitored with the UV-Vis spectroscopy method. The UV-Vis spectra of MB solution did not have any strange peaks in 200-800nm indicating that MB degradation generated simple products. UV-Vis spectra of MB solution reached to the baseline after 105 mins irradiated using SZO4% thin film. Moreover, degradation of aqueous MB solution in the presence of thin films under solar light with UV index 7-8 was slower than UV light; however, the Sn doped thin films still had better catalytic activity than the ZnO film (SZO4% > SZO2% > ZnO). After 105 mins, MB was degraded 84.3% in the case of SZO4% in solar light as compared with 97.9% in UV light. The reaction also followed the first-order reaction. The result indicated a potential application of the thin films in direction of green lives in near future.
Środowisko / Chemia / Biotechnologia / Nanotechnologia
Ochrona własności intelektualnej
poziom gotowości technologicznej