Synthesis of ZnO–Co₃O₄ Nanocomposites for Efficient Methylene Blue Degradation under Solar Light Irradiation

The release of pollutants into water reservoirs is harmful to aquatic life and poses serious health risks to humans, which is a significant issue everywhere in the world. Photocatalytic degradation of organic dyes has attracted the attention of researchers in order to purify industrial wastewater. In this work, ZnO is incorporated with Co₃O₄ using the template-free hydrothermal method and co-precipitation method. After studying the structural and morphological characteristics with XRD and FESEM, optical properties and bandgap were investigated using UV-visible spectroscopy and PL spectroscopy, which gives information about the alterations in the band gap of nanocomposite while revealing defects in the materials. The photocatalytic activity was investigated for methylene blue (MB) over the tenure of 60 min. The composite exhibited 3.6- and 9.3-times better degradation as compared to pristine Co₃O₄ and ZnO, respectively. The cyclic stability test and the scavenger experiments were also performed. The results suggest that the material can be used for industrial effluent purification purposes.