Ultrasonically-assisted mechanochemical synthesis of zinc aluminate spinel from aluminium-rich layered double hydroxide

• Published in: Journal of solid state chemistry Vol. 272; pp. 227 - 233
• Main Authors: Szabados, Márton, Kónya, Zoltán, Kukovecz, Ákos, Sipos, Pál, Pálinkó, István
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-04-2019
• Subjects: Mechanochemical treatment; SEM; Thermal characterization techniques; Ultrasonic irradiation; XRD; Zinc aluminate spinel; ZnAl2-LDH; ZnAl2-LDH; Thermal characterization techniques; Zinc aluminate spinel; Ultrasonic irradiation; IR; SEM; XRD; Mechanochemical treatment
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2019.02.020

An ultrasonically-assisted mechanochemical method was further improved to increase the yield of high-quality ZnAl2-LDH with carbonate interlayer anions. In the LDH formation, the rarely studied temperature, power and pulse character of ultrasound irradiation were investigated to determine the optimal parameters for the synthesis. The as-prepared samples were milled with varying the grinding frequency in order to convert the layered hydroxide structure into ZnAl2O4 spinel. This was the first time that ZnAl2O4 spinel formation was induced mechanochemically. The main method to identify the effects of ultrasonic and mechanochemical treatments was X-ray diffractometry; however, infrared spectroscopy, scanning electron microscopy, and thermal analysis were also applied to follow and compare the mechanochemically induced spinel formation to the more frequently used heat treatment.
The thermal and the mechanochemical transformations of ZnAl-LDH to ZnAl spinel were followed and the resulting materials were compared. [Display omitted]
•Developing further the ultrasonic mechano-preparation of aluminium-rich ZnAl2-LDH.•Mapping the ultrasonic irradiation characteristics on LDH formation.•ZnAl2O4 spinel generation by mechanical and heat treatment of the as-prepared LDH.•Following the LDH degradation and evolution of spinel on two routes by XRD, IR, SEM.