Water remediation induced by anatase-TiO2 nanoparticles: unveiling the selectivity of reactive species in persistent organic pollutant photodegradation

Abstract

This study sheds light on the complex mechanisms of heterogeneous photocatalysis induced by UV–TiO2 irradiation, revealing the key reactive species responsible for the decomposition of persistent organic pollutants in water. By employing a range of scavengers and evaluating 50 diverse organic pollutants, including pesticides, pharmaceuticals, and dyes, we uncover the crucial roles of holes, electrons and different reactive oxygen species in the photodegradation process. Our findings highlight the importance of molecular structure, electronic nature, and redox potential in determining the decomposition pathway, and demonstrate the potential for tailored photocatalytic approaches to target specific pollutants. This research also provides valuable insights into the dynamic interactions between scavengers and photoreactive species, illuminating how key external factors—including pH, adsorption catalyst capacity, and light source characteristics—could alter the selectivity towards the target pollutant. These finding lay the groundwork for developing optimized water treatment strategies, enabling more precise and efficient pollutant degradation.