Plasmonic-Enhanced Hierarchical CNT/Ag/CuO Nanocomposites for Superior Catalytic Degradation of Methyl Orange Dye

This study reports the synthesis and catalytic evaluation of multi-component nanocomposites based on carbon nanotubes (CNTs), silver nanoparticles (Ag NPs), and copper oxide nanoparticles (CuO NPs) for the efficient degradation of methyl orange (MO) dye. The nanocomposites were fabricated via laser ablation, enabling controlled decoration of CNTs with CuO and Ag nanoparticles. X-ray diffraction analysis confirmed the preservation of CNT graphitic structure alongside the formation of crystalline CuO and FCC Ag phases, with increasing silver content achieved by extended ablation times. Optical characterization revealed enhanced visible-light absorption and plasmonic effects due to Ag incorporation, promoting efficient charge separation. Catalytic degradation experiments demonstrated that the CuO/Ag/CNTs composite exhibited superior MO degradation efficiency when the ablation of Ag target is up to 45 min, achieving approximately 90% removal under mild conditions, outperforming individual components and binary composites. Kinetic studies indicated pseudo-first-order reaction behavior with diffusion limitations at later stages. Adsorption isotherm analysis favored the Langmuir model, suggesting monolayer adsorption on homogeneous active sites. The synergistic combination of CNTs, CuO, and Ag NPs in a hierarchical nanostructure provides a promising platform for wastewater treatment applications through enhanced catalytic activity and stability.