Monitoring the process of formation of ZnO from ZnO2using in situ combined XRD/XAS technique

Thomas Daley; Kwasi B Opuni; Edwin Raj; Andrew J Dent; Giannantonio Cibin; Timothy I Hyde; Gopinathan Sankar

doi:10.1088/1361-648X/abfb91

Monitoring the process of formation of ZnO from ZnO₂using in situ combined XRD/XAS technique

J Phys Condens Matter. 2021 May 31;33(26). doi: 10.1088/1361-648X/abfb91.

Authors

Thomas Daley¹, Kwasi B Opuni¹, Edwin Raj², Andrew J Dent³, Giannantonio Cibin³, Timothy I Hyde², Gopinathan Sankar¹

Affiliations

¹ Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom.
² Johnson Matthey Technology Centre, Blount's Court Sonning Common, Reading RG4 9NH, United Kingdom.
³ Diamond Light Source, Harwell Science & Innovation Campus, Oxfordshire OX11 0DE, United Kingdom.

PMID: 33902025
DOI: 10.1088/1361-648X/abfb91

Abstract

Use ofin situcombined x-ray diffraction and x-ray absorption spectroscopy for the study of the thermal decomposition of zinc peroxide to zinc oxide is reported here. Comparison of data extracted from both x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) with thermo gravimetric analysis (TGA) enabled us to follow the nature of the conversion of ZnO₂to ZnO. A temperature range between 230 °C and 350 °C appears to show that a very poorly crystalline ZnO is formed prior to the formation of an ordered ZnO material. Both the decrease in white line intensity in the Zn K-edge XANES and resulting lower coordination numbers estimated from analysis of the Zn K-edge data of ZnO heated at 500 °C, in comparison to bulk ZnO, suggest that the ZnO produced by this method has significant defects in the system.

Keywords: ZnO; ZnO2; combined XRD/XAS; in situ.

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