Synthesis, characterization and spectroscopic investigations of novel nano multi-metal oxide Co3O4·CeO2·ZnO

• Novel nanocomposite Co3O4·CeO2·ZnO was synthesized and characterized.
• PL behavior of Co3O4·CeO2·ZnO depends on excitation wavelength.
• PL is contrary to Kasha’s rule of excitation wavelength dependence.
• The NBE and blue emissions were detected at 365–371 and 407–454 nm.
• The green and orange emissions were observed at 513–519 and 593 nm.

A novel multi-metal nanocomposite, Co3O4·CeO2·ZnO has been prepared by co-precipitation of their carbonates from aqueous solutions of the metal nitrates following calcining and annealing 5 h at 450 °C and 10 h at 950 °C. Co3O4·CeO2·ZnO has been characterized by XRD, SEM, EDS, IR and PL spectra. The crystallite size of the as-synthesized sample varies in the range of 9–33 nm and those of the annealed sample in the range of 19–42 nm. Emissions of Co3O4·CeO2·ZnO were observed in UV and visible region at different excitations. Excitation wavelength dependent PL behavior of Co3O4·CeO2·ZnO has been observed in acetone. This PL property is contrary to the well-known Kasha’s rule of excitation wavelength dependence of emission spectrum.

PL spectra of Co3O4·CeO2·ZnO at 220, 250 and 270 nm excitations in acetone showing NBE emission and blue emissions.Figure optionsDownload as PowerPoint slide