Effect of drying time on the properties of hydrothermal grown ZnO two-dimensional nanosheets as photocatalysts

In this research, a simple and modified hydrothermal method has been used to synthesize two-dimensional zinc oxide nanostructures. Then, the effect of hydrothermal growth time as one of the main post-treatment parameters on the grown structures was investigated. For this purpose, X-ray diffractometry (XRD) and Field emission scanning electron microscopy (FESEM) were utilized to analyze the morphology and crystalline structure of the samples. It was observed that the grown structures have the sheet-like morphology which their thickness decreases with increasing dying time at 80 °C from 9 to 15 h. The XRD results showed that the structures have been crystalized into the hexagonal phase with (101) as the preferred growth orientation. In addition, decrease in the size of the crystallites (calculated from XRD) was concluded with increasing heating time. In the end, the photocatalytic activity of the samples was investigated, and as a result of this investigation, the sample that was heated for 15 h had a better performance in the degradation of methylene blue.