Enhancing xylene degradation by core-shell TS-1@TiO₂ in a bubble reactor with ultraviolet/H₂O₂

Volatile organic compounds (VOCs) in the atmosphere pose a critical global challenge due to their detrimental health effects. The ultraviolet (UV)/Fenton-like system has shown promise for VOC degradation. However, maintaining long-term catalytic efficiency by minimizing intermediate byproduct accumulation remains key challenges. In this study, a novel core-shell catalyst is developed which composed of anatase-phase titanium dioxide (TiO₂) nanoparticles deposited on titanium silicalite-1 (TS-1) via a Stöber method in an ethanol/ammonia mixture. The TS-1@TiO₂ structure promotes efficient spatial separation of photogenerated electrons and holes under UV irradiation, enhancing the activation of H₂O₂ to yield highly reactive free radicals (OH, OOH and O₂^-) for effective xylene degradation. In a UV/H₂O₂ bubble reactor, the TS-1@TiO₂ catalyst demonstrates stable xylene degradation efficiency (75 % over 200 min), surpassing the performance of standalone TS-1 (53.2 %) and TiO₂ (57.1 %). This design addresses critical challenges in sustained radical generation and intermediate suppression, offering a robust strategy to improve the longevity and efficiency of UV/H₂O₂ systems for environmental remediation.