Photodegradation performances and transformation mechanism of sulfamethoxazole with CeO2/CN heterojunction as photocatalyst

Sulfamethoxazole (SMX) is a ubiquitous sulfonamides in aquatic environment which is difficult to be removed by traditional wastewater treatment technologies. Herein, heterogenous nanocomposites of CeO2 and graphite carbon nitride (CN) were prepared and applied to photodegrade SMX under visible light irradiation. With the optimized mass ratios, the photocatalyst 5CeO(2)/CN (CeO2, 5% mass ratio) showed robust ability in absorbing visible light and promoting separation efficiency of photoinduced electrons and holes. Consequently, the removal efficiency of SMX with 5CeO(2)/CN reached 99.2% after irradiation for an hour, 7.56% and 91.83% higher than that with pure CN and CeO2. (OH)-O-center dot, O-center dot(2)- and h(+) were proved to be the active species towards SMX photodegradation, and O-center dot(2)- was the dominant one. The intermediate products were identified and the possible pathways of SMX by photocatalysis were proposed in this study.