A Hybrid Synthesis Approach: Tailoring Photocatalytic Activity of Co3O4 Nanoparticles by PEG Functionalization

Abstract

This study presents a novel fusion of precipitation and hydrothermal methods for the synthesis of polyethylene glycol (PEG)-functionalized cobalt oxide (Co3O4) nanoparticles. The synthesized PEG/Co3O4 nanoparticles characterized using various techniques to elucidate their structure, composition, properties and application. The XRD analysis confirmed the formation of cubic phase of Co3O4 with a crystallite size of 2.04 nm. Two direct bandgap (Eg) transitions were observed at energy levels of 1.68 and 2.5 eV, exhibiting intensities that exceeded those reported in prior studies. The synthesized nanoparticles exhibited distinct structural features as revealed by FESEM and HRTEM investigations. Furthermore, the FTIR analysis provided evidence of interactions between PEG and Co3O4, suggesting successful functionalization. The high crystallinity of the PEG-mediated Co3O4 nanoparticles was further confirmed by the selected area electron diffraction (SAED) pattern. The XPS analysis revealed the presence of Co2+ and Co3+ ions, along with defect sites, confirming the successful synthesis of Co3O4 NPs with controlled oxidation states. These findings offer valuable insights into the chemical composition and electronic structure of the synthesized PEG-mediated Co3O4 nanoparticles. The photocatalytic activity of the PEG/Co3O4 nanoparticles was evaluated through the degradation of Congo red dye, a typical azo dye pollutant. The study revealed that PEG/Co3O4 (dose 200 mg L-1) acted as an efficient photocatalyst for Congo red degradation. These results suggest that PEG-mediated Co3O4 nanoparticles hold promising potential as efficient photocatalysts for the treatment of wastewater containing organic contaminants.