Synergistic effects of Ni-doped Co3O4 coupled with ZnO nanoparticles for enhanced photocatalytic decolorization of reactive red 141 dye

Abstract

Developing high-performance photocatalytic materials to remove contaminants from water sources is vital for health and environmental conservation. In this study, ZnO/Ni-doped Co3O4 heterojunction nanocomposites were successfully fabricated by sol-gel method and utilized as one of the most promising photocatalysts for the photocatalytic decolorization of reactive red 141 (RR141) dye. The concentration of Ni dopant was selected from 0 to 8 wt%. The prepared photocatalysts were characterized by X-ray diffraction (XRD) and field emission-scanning electron microscope (FE-SEM), energy dispersive X-ray spectra (EDS), and UV-visible diffuse reflectance spectra (UV-vis DRS) analysis. The optical band gap of ZnO nanoparticles, Co3O4 nanoparticles, ZnO/Co3O4, ZnO/2Ni-Co3O4, ZnO/5Ni-Co3O4, and ZnO/8Ni-Co3O4 nanocomposites was found to be 3.25, 2.54, 2.9, 3.78, 2.71, and 2.56 eV, respectively. The photocatalytic results demonstrated robust performance for ZnO/5Ni-Co3O4 nanocomposite in the decolorization of RR141 dye, achieving output as high as 97.4% under 100 min light irradiation. This enhanced photocatalytic efficiency can be attributed to the synergistic effects of Ni doping into Co3O4 lattice and its coupling with ZnO to form an n-p heterojunction ZnO/Ni-Co3O4 nanocomposite, which effectively improves light absorption and separates photogenerated charge carriers on the surface of the nanocomposite