Enhanced visible-light photocatalytic degradation of PET using CuO/TiO2 heterostructure nanocomposites: A comprehensive study

Plastic pollution represents a significant global environmental challenge requiring advanced mitigation strategies. This investigation systematically examines the photocatalytic degradation performance of CuO/TiO 2 composites to prove the feasibility of rapid degradation of polyethylene terephthalate (PET). Various advanced characterization methodologies, including Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD), and X-ray Photoelectron Spectroscopy (XPS), were employed to verify the successful synthesis of nanocomposites and elucidate their distinctive structural attributes and superior photocatalytic functionality. Implementation of a two-step photocatalytic degradation protocol enabled PET to achieve remarkable mass reduction of 97.39 ± 0.79 % after 2 h illumination, representing approximately 30-fold enhancement compared to untreated PET samples. Furthermore, the use of PET film as a pollutant verified the practical feasibility of this method, highlighting the potential of CuO/TiO 2 composites for plastic degradation. Complementary free radical quenching experiments and electron paramagnetic resonance (EPR) spectroscopic analyses identified hydroxyl radicals (•OH) as the predominant active species governing PET decomposition pathways. The proposed mechanistic model elucidates the synergistic effects of interfacial energy band modifications between constituent semiconductor components, which critically enhance photoinduced charge carrier separation efficiency. Notably, the study not only achieved the efficient degradation of PET but also provided an efficient method for solving environmental plastic pollution in the future.