Sunlight activation of persulfate by g-C3N4@FexTi3-xO4 photocatalyst for atrazine degradation

Abstract

Atrazine (ATZ) is a highly persistent, not readily decomposable triazine herbicide that is widely distributed in the environment, causing not only ecological impacts but also harm to human health. In this study, g-C₃N₄@Fe_xTi_3-xO₄ catalysts were prepared for photocatalytic activation of peroxydisulfate (PDS) to degrade ATZ in water. An exploration was conducted into the impact of various environmental factors on ATZ degradation, and a subsequent analysis was performed on the degradation mechanism. The results showed that g-C₃N₄@Fe_xTi_3-xO₄ exhibited excellent PDS activation properties and removed more than 99 % of ATZ in water within 120 min. The ATZ degradation efficiency increased significantly with the increase of catalyst dosing (50 – 500 mg/L) and PDS concentration (0.1 – 2 mM). Catalysts demonstrate exceptional degradation performance under both neutral and acidic conditions, particularly under acidic conditions where the degradation time of atrazine is reduced to 40 min. Moreover, the electron paramagnetic resonance (EPR) and free radical quenching experiments confirmed the occurrence of a free radical conversion process, which primarily includes the active species of ⋅OH and${\mathrm{SO}}_4^{·-}$. And ⋅OH, ${\mathrm{SO}}_4^{·-}$and h⁺ is involved in the process of ATZ degradation. Results of degradation pathways and toxicity analysis has demonstrated g-C₃N₄@Fe_xTi_3-xO₄ to be highly effective in reducing the ecological impact of ATZ, and the catalytic material possesses excellent recycling potential, making it ideal for use in real-world environments.