Photocatalytic activity of flower-like ZnO derived by a d-glucose-assisted sonochemical method

This work reports the preparation of flower-like ZnO for applications in the catalytic oxidation of methyl orange (MO) in aqueous solution. The wurtzite ZnO samples with flower-like morphologies were obtained via a d-glucose-assisted sonochemical method. Effects of the presence of glucose, sonication times (0, 10, and 20 min) and calcination temperatures (300, 400, and 500 C) on the morphology of the catalysts were investigated. Results from this work suggest that d-glucose played an important role in the formation of flower-like morphologies and the sonication processes further enhanced the flower-like characteristic ordering. The majority of ZnO samples prepared in this work had rather high photocatalytic activity after 45 min, with MO degradation greater than 85 % of the initial concentration. These results suggest that the photocatalytic activity of ZnO after 45-min reaction time correlates well with the specific surface area, and the number of oxygen vacancies present in the materials. The solubility of flower-like ZnO samples in the dye solution was measured to be 19.2 ppb after 24-h reaction time.