| Abstract Scope |
Surface hydroxyl groups play a central role in determining the photocatalytic efficiency of titanium dioxide (TiO₂) nanoparticles during polymer degradation. This presentation examines how hydroxylated TiO₂ surfaces facilitate charge trapping, water activation, and reactive oxygen species (ROS) generation, thereby initiating oxidative degradation of persistent polymers. The influence of hydroxyl density, crystal phase, particle morphology, and interfacial adsorption on charge transfer and degradation kinetics is critically discussed. Particular attention is given to the formation of hydroxyl radicals and superoxide species responsible for polymer oxidation, chain scission, and molecular weight reduction under light irradiation. Current strategies for tailoring surface hydroxyl chemistry through defect engineering, surface modification, and heterojunction construction are also evaluated. Understanding these interfacial processes provides a mechanistic foundation for designing highly efficient TiO₂ photocatalysts for sustainable plastic waste remediation and environmental decontamination. |