Synthesis of dehydrated zinc borates using the solid-state method: Characterization and investigation of the physical properties

Abstract

In this study, several dehydrated zinc borates are synthesised from ZnO and H3BO3 via the solid-state method. Five different ZnO: H3BO3 mole ratios (1:2-1:6) are prepared and used in the experiments. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopy techniques are used to characterize the products. Furthermore, scanning electron microscope (SEM) is used to investigate the surface morphologies. Additionally, the electrical resistivity and optical energy gaps of the dehydrated zinc borate samples synthesised at reaction temperatures were determined using the current/voltage characteristics and Ultraviolet-visible spectroscopy (UV-Vis) absorption measurements. Based on the experimental results, major phases of ZnB4O7 and Zn4O(B6O12) compounds were synthesised at 800 degrees C after a reaction time of 240 min and at 900 degrees C at all reaction temperatures between 60 and 240 min. The dehydrated zinc borate particle sizes were found to be 395.53 nm-2.36 mu m. The electrical bulk resistivity was determined to be 10(7)-10(8) Omega.m, and the optical energy band gaps were determined to be approximately 3.26 eV and 2.21 eV.