A Novel Synthesis of Zinc Borates from a Zinc Oxide Precursor via Ultrasonic Irradiation

Abstract

In this study, zinc borate hydrate (Zn 3 B 6 O 12 · 3.5H 2 O) was synthesized from zinc oxide (ZnO) and boric acid (H 3 BO 3 ) via a novel method of ultrasonic irradiation. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy were used to characterize the synthesized products. Scanning electron microscopy (SEM) was used to determine the effects of reaction time and reaction temperature on the morphology of the products. Thermal dehydration kinetics were studied using thermal gravimetry and differential thermal gravimetry analysis (TG/DTA). The Doyle and Kissinger non-isothermal kinetic methods were used to analyse the TG/DTA data. The XRD results confirmed the successful synthesis of Zn 3 B 6 O 12 · 3.5H 2 O at a range of reaction temperatures and times. Additionally, FT-IR and Raman analysis of the products identified peaks specific to zinc borate. Using the methods of Doyle and Kissinger, the activation energies of thermal dehydration of zinc borate were found to be 341.61 kJ/mol and 390.17 kJ/mol, respectively.

An accelerated and effective synthesis of zinc borate from zinc sulfate using sonochemistry

“…The compounds' XRD patterns with the highest XRD scores are given in Figure 2. The characteristic peaks are in mutual agreement with the studies reported in the literature (Ersan et al, 2016;Kipcak et al, 2014Kipcak et al, , 2015Kipcak et al, , 2016Vardar et al, 2017). In addition, the as-obtained XRD scores were slightly higher than those previously reported in the literature (Table 1).…”

“…According to the XRD results, the as-synthesized compound was defined as "zinc oxide borate hydrate (Zn 3 B 6 O 12 •3.5H 2 O)" with the pdf No. "00-035-0433" and was identical to that previously reported in the literature (Bardakci et al, 2013;Ersan et al, 2016;Kipcak et al, 2014Kipcak et al, , 2015Kipcak et al, , 2016Vardar et al, 2017). The as-synthesized zinc borate compound's XRD results are given in Figure 1.…”

“…The hydrothermal synthesis of zinc borates has been widely studied and reported in the literature. In our research group, we have studied the ultrasonic synthesis of zinc borates using ZnO and Zn 5 (CO 3 ) 2 •(OH) 6 as the starting materials (Ersan et al, 2016). Due to the high cost of the starting materials used these two studies with respect to ZnSO 4 •7H 2 O, this study's novelty is the cheap and rapid synthesis's of zinc borate by using the method of sonochemistry.…”

A novel synthesis of nanoflower-like zinc borate from zinc oxide at room temperature

“…The bands from 1190 cm -1 to 1120 cm -1 correspond to the stretching vibration of the boronoxygenhydrogen [δ(B-O-H)] [25]. The bands between 860 cm -1 and 800 cm -1 correspond to the asymmetric stretching vibration of the four-coordinate boron to oxygen bands [ν as (B 4 -O)] [26].…”

“…The band of ν as (B 4 -O) appears at 1048 cm −1 , meanwhile the band of νp(B(OH) 4 ) is observed at approximately 755 cm −1 . Moreover, the peak at 664 cm −1 is assigned to the bending of γ(B 3 -O), the peak of δ (B 4 -O) appears at around 578 cm −1 , and the peak at 297 cm −1 corresponds to the bending of B 3 -O [26].…”