Abstract:
Transition metal oxide nanocomposites are attracting significant research interest due to their
potential applications in optoelectronic devices, solar cells, photocatalysis, and antibacterial
materials. This study focuses on CuO-Zn1-xCoₓO (x = 0.0, 0.02, 0.04, 0.055, and 0.07) metal
oxide nanocomposites synthesized by the sol-gel combustion method. The synthesized
nanocomposites were characterized using X-ray diffraction (XRD), Fourier transform
infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) analysis, ultraviolet-visible
(UV-vis) spectroscopy, and photoluminescence (PL) spectroscopy. XRD confirmed the
formation of monoclinic crystal structure of CuO and hexagonal crystal structure of ZnO in
all nanocomposite compounds. An average crystal size obtained from XRD parameters was
ranging from 26.8 to 31.8 nm, confirming the formations of nanostructured since the values
are in the range of nano scale. Moreover, FTIR analysis verified the presence of functional
groups consistent with the composite structure. BET measurements revealed high surface
areas (48.86 to 51.07 m²/g) for all samples. UV-vis spectroscopy indicated prominent
absorption in the UV and visible regions, with Co ions doped nanocomposites exhibiting
enhanced absorption compared to pristine CuO-ZnO composite. The band gap energy,
calculated from UV-vis data, decreased from 3.27 eV to 2.88 eV with increasing Co doping.
The PL analysis confirmed a reduction in electron-hole recombination when Co ions doped
into CuO-ZnO nanocomposite, Photocatalytic activity tests revealed enhanced performance
against methylene blue dye under UV light irradiation for Co ions doped nanocomposites.
Among the samples, CuO-Zn₀.₉₄₅Co₀.₀₅₅O exhibited the highest photocatalytic activity.
