Investigating the effects of hydrothermal temperature on morphology-controlled synthesis of flower-shaped ZnO microstructures

摘要

The hydrothermal synthesis and morphology-dependent properties of flower-shaped ZnO microstructures have been extensively described in this study. The growth of flower-shaped ZnO microstructures has been conducted in HMT aqueous solutions containing zinc nitrate tetrahydrate precursor in three different hydrothermal temperatures (100 degrees C, 150 degrees C, and 200 degrees C). Morphological observations and structural analysis have been performed using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transfer infrared spectroscopy (FT-IR), and Raman spectroscopy. Morphological studies have indicated a transition from sheet-like petals to rod-like structures for flower-shaped architectures with the increase of reaction temperatures. XRD patterns have revealed single-crystalline behavior for as-synthesized ZnO microstructures. Crystalline quantities have been investigated using a variety of X-ray line broadening analysis techniques including Debye-Scherrer and Williamson-Hall methods. UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) has been employed to carry out the optical studies and estimate optical band gap energies. The optical results have suggested morphology-dependent responses for flower-shaped ZnO microstructures.