Hydrothermal synthesis of CuO and CeO2/CuO nanostructures: spectroscopic and temperature dependent electrical properties

Romang Bosigo, Lucia M. Lepodise, Alex Kuvarega, Cosmas Muiva

Research output: Contribution to journalArticlepeer-review

Abstract

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.

Original languageEnglish
Pages (from-to)7136-7152
Number of pages17
JournalJournal of Materials Science: Materials in Electronics
Volume32
Issue number6
DOIs
Publication statusPublished - Mar 2021

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Fingerprint

Dive into the research topics of 'Hydrothermal synthesis of CuO and CeO<sub>2</sub>/CuO nanostructures: spectroscopic and temperature dependent electrical properties'. Together they form a unique fingerprint.

Cite this