Visible-Light-Driven Photocatalytic Hydrogen Production from Polystyrene Nanoplastics Using Pd/TiO₂ Nanoparticles

The accumulation of microplastics and nanoplastics in aquatic environments has raised significant concerns in recent years, given the potential health risks to both aquatic ecosystems and humans; due to their nanometer size, they enter the food chain of aquatic species and consequently that of humans too. This study presents an efficient plasmonic photocatalyst for degrading polystyrene nanoplastics (PS NPs), while simultaneously generating green hydrogen in the process. Blank controls show that the presence of PS NPs is necessary for H₂ evolution, since under identical conditions, it does not occur in their absence. A series of visible light-responsive plasmonic photocatalysts consisting of TiO₂ nanoparticles (NPs) supporting Pd, Au, Pt, and Ag NPs were prepared via the impregnation method. Among the synthesized nanoparticle photocatalysts, the 3 wt % Pd/TiO₂ NP photocatalyst exhibited superior hydrogen generation, producing 1329.76 μmol_H2 g_cat ^-1 after 2 h of irradiation, while also achieving a reduction in the average PS NP diameter. This study illustrates the potential of solar NP photocatalysis for environmental remediation and simultaneous hydrogen evolution.