<p>Microplastics (MPs) exposed to environmental weathering, particularly UV radiation, undergo significant modifications to their surface properties, thereby enhancing their potential to adsorb and transfer pollutants such as heavy metals (HMs). This study examines the adsorption behavior of zinc (Zn(II)) onto virgin and UV-aged polyethylene terephthalate (PET) and polypropylene (PP) MPs subjected to up to 30 days under UV exposure. The aging process altered the morphological and physicochemical characteristics of the MPs as evidenced by characterization, which revealed the increased surface roughness, cracking, and enhanced hydrophilicity. Surface chemistry changes were further analyzed using FTIR and XRD; revealing the development of new functional groups like carbonyl (C = O) and hydroxyl groups (OH) in association with improved crystallinity indicates the emerging new active adsorption sites. Batch adsorption experiments were conducted under varying aging durations (0 to 30 days) and contact time (0 to 48 h). Results showed that UV aging significantly enhanced Zn(II) adsorption capacity for PET and PP, with adsorption equilibrium reached at 24 h. Kinetic data best fit the PSO model (<i>R</i>² &gt; 0.95) indicating chemisorption as the dominant mechanism, while the isotherms more closely confirmed to the Langmuir model, suggesting homogeneous monolayer adsorption. This research highlights the understanding of the adsorption behavior of MPs and takes the effect of UV aging into account.</p> Graphical abstract <p></p>