XPS study of Cu₃TeO₆ semiconductors synthesized at different pH values
Jussila, Laura (2023-05-19)
Jussila, Laura
L. Jussila
19.05.2023
© 2023 Laura Jussila. Ellei toisin mainita, uudelleenkäyttö on sallittu Creative Commons Attribution 4.0 International (CC-BY 4.0) -lisenssillä (https://creativecommons.org/licenses/by/4.0/). Uudelleenkäyttö on sallittua edellyttäen, että lähde mainitaan asianmukaisesti ja mahdolliset muutokset merkitään. Sellaisten osien käyttö tai jäljentäminen, jotka eivät ole tekijän tai tekijöiden omaisuutta, saattaa edellyttää lupaa suoraan asianomaisilta oikeudenhaltijoilta.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:oulu-202305191917
https://urn.fi/URN:NBN:fi:oulu-202305191917
Tiivistelmä
For this thesis, X-ray photoelectron spectroscopy (XPS) was used to study copper tellurates synthesized at different pH values using novel hydrothermal synthesis. Copper tellurate compound (Cu₃TeO₆) is a semiconductor that belongs to the metal tellurate family and exhibits fascinating electronic and magnetic properties like antiferromagnetism. It also has applications in ceramics and as a possible drug sensor. The new hydrothermal synthesis route provides better control over the composition and size of the nanoparticles. Since there is high interest in these materials and a new synthesis method has been used, a thorough characterization is needed.
XPS is a surface-sensitive method based on the photoelectric effect and is suitable for identifying elements and chemical states in the sample. Here, XPS spectra were peak fitted to identify the binding energies of copper, tellurium, and oxygen species in the samples. Copper was revealed to be Cu(II) species, tellurium spectra included both Te(IV) and Te(VI) components, meanwhile, oxygen spectra had a strong shoulder peak for either hydroxide or defective oxygen, the latter of which would explain the unexpected Te(IV) peak. The results also showed the presence of a hydroxide component, which was removed by calcination. Chemical shifts were observed for copper and tellurium peaks. The findings of this study provide insights into the synthesis and properties of copper tellurates, which can guide future research.
XPS is a surface-sensitive method based on the photoelectric effect and is suitable for identifying elements and chemical states in the sample. Here, XPS spectra were peak fitted to identify the binding energies of copper, tellurium, and oxygen species in the samples. Copper was revealed to be Cu(II) species, tellurium spectra included both Te(IV) and Te(VI) components, meanwhile, oxygen spectra had a strong shoulder peak for either hydroxide or defective oxygen, the latter of which would explain the unexpected Te(IV) peak. The results also showed the presence of a hydroxide component, which was removed by calcination. Chemical shifts were observed for copper and tellurium peaks. The findings of this study provide insights into the synthesis and properties of copper tellurates, which can guide future research.
Kokoelmat
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