Background:
During past two decades, functional nanomaterials have received great attention
for many technological applications such as catalysis, energy, environment, medical and sensor
due to their unique properties at nanoscale. However, copper oxide nanoparticles (NPs) such as
CuO and Cu2O have most widely investigated for many potential applications due to their wide
bandgap, high TC, high optical absorption and non-toxic in nature. The physical and chemical properties
of CuO and Cu2O NPs are critically depending on their size, morphology and phase purity.
Therefore, lots of efforts have been done to prepare phase CuO and Cu2O NPs with different morphology
and size.
Method:
The synthesis of cupric oxide (CuO) and cuprous oxide (Cu2O) NPs using copper acetate as
a precursor by varying the reducing agents such as hydrazine sulphate and hydrazine hydrate via
sonochemical method. The phase, morphology and crystalline structure of a prepared CuO and Cu2O
NPs were investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Field emission
scanning electron microscopy (FESEM), Energy dispersive X-ray (EDS) and UV-Visible Diffuse
reflectance spectroscopy (DRS).
Results:
The phase of NPs was tuned as a function of reducing agents.XRD patterns confirmed the
formation of pure phase crystalline CuO and Cu2O NPs. FTIR peak at 621 cm-1 confirmed Cu(I)-O
vibrations, while CuO vibrations confirmed by the presence of two peaks at 536 and 586 cm-1. Further
investigation was done by Raman, which clearly indicates the presence of peaks at 290, 336, 302
cm-1 and 173, 241 cm-1 for CuO and Cu2O NPs, respectively. The FESEM images revealed rod-like
morphology of the CuO NPs while octahedral like shape for Cu2O NPs. The presence of elemental
Cu and O in stoichiometric ratios in EDS spectra confirms the formation of both CuO and Cu2O NPs.
In summary, CuO and Cu2O NPs were successfully synthesized by a sonochemical
method using copper acetate as a precursor at different reducing agents. The bandgap of CuO and
Cu2O NPs was 2.38 and 1.82, respectively. Furthermore, the phase purity critically depends on reducing
agents.
