TY - JOUR
T1 - Hydrothermal synthesis of CuO and CeO2/CuO nanostructures
T2 - spectroscopic and temperature dependent electrical properties
AU - Bosigo, Romang
AU - Lepodise, Lucia M.
AU - Kuvarega, Alex
AU - Muiva, Cosmas
N1 - Funding Information:
The authors greatly recognise the financial backing from the Botswana International University of Science and Technology Research Initiation Grant (DVC/RDI/2/1/161(R00020) and DVC/RDI(SG00101).
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/3
Y1 - 2021/3
N2 - In this study, CuO and CeO2/CuO nanostructures were successfully synthesized via a hydrothermal route. The structure, morphology, composition and optical properties of these nanostructures have been studied using various techniques. X-ray diffraction (XRD) analysis showed the formation of monoclinic crystalline phase of CuO with a decrease in the crystallinity of the samples as the Ce content increased. Scanning electron microscopy (SEM) acquired images showing that increased Ce incorporation induces transformation of morphology from spherical to rod-like nanostructures. Energy-dispersive X-ray spectroscopy (EDS) mapping showed that Ce was homogeneously distributed onto the CuO matrix. UV/Vis/NIR spectrophotometer measurements depicted a blue shift in the bandgap from 2.0 to 3.5 eV for 0%-6% Ce and then 3.2 eV for 8% Ce. Brunauer Emmett Teller (BET) analysis revealed enhanced porosity with the incorporation of cerium. Raman spectroscopy results confirmed the presence of the Ag(296 cm−1), Bg(346 cm−1) and Bg(631 cm−1) modes belonging to CuO. The F2g Raman active mode observed at 454 cm−1 belongs to CeO2. Fourier transform infra-red (FTIR) measurements showed stretching vibrations of Cu–O. The CeO2/CuO samples exhibited enhanced temperature-controlled Dc conductivity with the 4% Ce sample showing the lowest activation energy, lowest Tmax (peak value of (dσ/dT)) and consequently the maximum conductivity peaking at a temperature of 503 K. The nature of conductivity was elucidated on the basis of the carrier hopping model.
AB - In this study, CuO and CeO2/CuO nanostructures were successfully synthesized via a hydrothermal route. The structure, morphology, composition and optical properties of these nanostructures have been studied using various techniques. X-ray diffraction (XRD) analysis showed the formation of monoclinic crystalline phase of CuO with a decrease in the crystallinity of the samples as the Ce content increased. Scanning electron microscopy (SEM) acquired images showing that increased Ce incorporation induces transformation of morphology from spherical to rod-like nanostructures. Energy-dispersive X-ray spectroscopy (EDS) mapping showed that Ce was homogeneously distributed onto the CuO matrix. UV/Vis/NIR spectrophotometer measurements depicted a blue shift in the bandgap from 2.0 to 3.5 eV for 0%-6% Ce and then 3.2 eV for 8% Ce. Brunauer Emmett Teller (BET) analysis revealed enhanced porosity with the incorporation of cerium. Raman spectroscopy results confirmed the presence of the Ag(296 cm−1), Bg(346 cm−1) and Bg(631 cm−1) modes belonging to CuO. The F2g Raman active mode observed at 454 cm−1 belongs to CeO2. Fourier transform infra-red (FTIR) measurements showed stretching vibrations of Cu–O. The CeO2/CuO samples exhibited enhanced temperature-controlled Dc conductivity with the 4% Ce sample showing the lowest activation energy, lowest Tmax (peak value of (dσ/dT)) and consequently the maximum conductivity peaking at a temperature of 503 K. The nature of conductivity was elucidated on the basis of the carrier hopping model.
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U2 - 10.1007/s10854-021-05423-6
DO - 10.1007/s10854-021-05423-6
M3 - Article
AN - SCOPUS:85101102885
SN - 0957-4522
VL - 32
SP - 7136
EP - 7152
JO - Journal of Materials Science: Materials in Electronics
JF - Journal of Materials Science: Materials in Electronics
IS - 6
ER -