Acoustic-assisted Fabrication, Characterization, and Photocatalytic Application of Ni ₂ O ₃ /NiO/rGO Nanocomposites

Introduction: This study introduces an innovative two-step approach to fabricate a highperformance Ni₂O₃/NiO/rGO nanocomposite photocatalyst. The process synergistically combines solvothermal precursor synthesis with calcination and high-energy ultrasonic irradiation, enabling the in-situ formation of a thin Ni₂O₃ layer on NiO quasi-sphere nanoparticles anchored to a reduced graphene oxide (rGO) matrix. Method: The incorporation of rGO significantly enhances charge separation, resulting in a dramatic increase in active surface area from 17.1 m²/g to 131 m²/g, and a substantial improvement in the photocatalytic degradation of the resilient Fluorescein dye—achieving an 81% degradation rate under UV light, compared to 36% with pristine NiO. Results: Comprehensive characterization, including FTIR, XRD, and XPS analyses, confirmed the NiO-Ni₂O₃ interface transformation, successful reduction of graphene oxide, and critical interactions between NiO and Ni₂O₃. Conclusion: This study highlights the promising potential of the Ni₂O₃/NiO/rGO nanocomposite for environmental remediation, particularly in the degradation of persistent organic pollutants.