The study of structural properties and photocatalytic activity of ZnO prepared by ultrasonic assisted precipitation method

Abstract

ZnO is a semiconductor that has excellent activity as photocatalyst under UV light region. ZnO is precipitated by adding oxalate acid onto zinc acetate dehydrate solution with ultrasonic assisted at various times and flattened at 500 °C. The structural properties of the ZnO samples are characterized by X-Ray Diffraction (XRD) and Brunauer-Emmett-Teller (BET). XRD result has confirmed the ZnO structure as hexagonal phase. Rietveld refinement of XRD pattern by La Beil method is employed to analyze the lattice parameters of ZnO. It provides that ZnO as wurtzite with accurate values. Debye-scherrer equation examines the crystallite size. It is confirmed that the crystallite size of ZnO is decreased by ultrasonic assisted at precipitation. BET result shows that ultrasonic assisted could increase the surface area of ZnO, which are 45.64 m2/g of ZnO without ultrasonic assisted and 143,487 m2/g of ZnO with ultrasonic assisted along 2 hours. The photocatalyst experiment is set up to analyze the photocatalytic activity of ZnO for degradation of methylene blue under UV light irradiation. By significantly that decolorization of methylene blue occurred at pH 10 for 30 minutes irradiation. The photocatalytic activity for ZnO samples with an hour and 2 hours ultrasonic assisted are 79.54 % and 86.50 % respectively, whereas ZnO sample without ultrasonic assisted is 70.90 %, and almost all of methylene blue contaminant have done degraded successfully after 120 minutes irradiation. According to the results, the structural properties and photocatalytic activity of ZnO are increased as consequence to the presence of ultrasonic assisted on precipitation.