Catalytic Degradation by Metal–Organic Hybrid Nanocomposites Based on Metal/Metal Oxide Nanostructured Materials Prepared by Pulsed Laser Ablation

The heterojunction based on plasmonic metals of Ag and Cu in the oxide form was synthesized and decorated carbon nanotubes to form Ag-Cu₂O/MWCNTs nanocomposites via a pulsed laser ablation process for water treatment. This study presents the synthesis and characterization of Ag/MWCNTs nanocomposites with different amounts of Cu₂O NPs using a novel two-step pulsed laser ablation technique for enhanced photocatalytic degradation of Congo Red dye under UV-visible-light irradiation. Structural and optical characterization techniques confirmed the successful formation of highly pure and crystalline nanocomposites, and the coupling of Ag NPs with Cu₂O NPs significantly enhanced visible-light absorption, making the nanocomposites highly effective for photocatalytic applications, which were systematically evaluated under varying pH, catalyst dosage, dye concentration, and irradiation time conditions. The results demonstrated that Ag-Cu₂O/MWCNTs with 60 min ablation (30min for Cu and 30 min for Ag), Ag-Cu₂O/MWCNTs(2), achieved the highest degradation efficiency of 99.43% for Congo Red (CR) dye at pH 8.0 and an optimal catalyst dosage. Kinetic studies and the degradation mechanism revealed that the photodegradation process followed the Langmuir-Hinshelwood pseudo-first-order model, with Ag-Cu₂O/MWCNTs(2) exhibiting the fastest degradation rate, outperforming other samples by degrading CR dye. This work underscores the potential of Ag-Cu₂O/MWCNTs nanocomposites as highly efficient photocatalysts for environmental remediation, particularly in the degradation of organic pollutants in wastewater. The findings provide valuable insights into optimizing photocatalytic processes for practical applications, offering a promising solution for sustainable water treatment and pollution control.