Studies on structural and optical properties of cobalt oxide nanoparticles using co-precipitation

Abstract

This article aimed to study the structural and optical properties of cobalt oxide (Co3O4) nanoparticles made using the co-precipitation method. The structural, morphological, and optical properties of as synthesized product were studied using an X-ray diffractometer (XRD), scanning electron microscopy (SEM), and UV–vis absorption spectroscopy, respectively. The XRD pattern of the sample with the refinement revealed the synthesized Co3O4 sample had a cubic structure with an average of 11.5 nm-sized crystallites. The SEM of the sample resulted in an agglomerated spherical shape. EDX confirmed the presence of cobalt (Co) and oxygen (O) elements in the sample. The Williamson-Hall method yields anisotropic Co3O4NPs with an average crystal size consistent with the XRD findings.Theoptical property has signified that the (direct, indirect) band gap of Co3O4NPs is between(1.60, 1.58) eV and (2.40, 2.13) eV, indicating (O2−→Co3+) and (O2−→Co2+) charge transferprocesses. Due to their optical properties, Co3O4nanoparticles may be used for photocatalysis, solar cells, supercapacitors, batteries, and sensing applications.