Shuttle-like CeO2/g-C3N4 composite combined with persulfate for the enhanced photocatalytic degradation of norfloxacin under visible light

In this work, the shuttle-like CeO 2 modified g-C 3 N 4 composite was synthesized and was combined with persulfate (PS) for the efficient photocatalytic degradation of norfloxacin (NOR) under visible light. Scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) emission spectra were used to characterize the structural and optical properties of the as-prepared catalysts. Active species trapping experiments demonstrated that additional sulfate radicals (·SO 4 - ) formed upon the addition of PS which could cooperate with superoxide radicals ( O 2 - ), holes (h + ) and hydroxyl radicals ( OH) to decompose NOR. Singlet oxygen ( 1 O 2 ) was also formed during the reaction and acted as an important active species. The degradation products of NOR were also identified and analyzed by using LC-MS technology , and the possible degradation mechanism and pathways were proposed and discussed. This work indicated that the shuttle-like CeO 2 modified g-C 3 N 4 coupled with PS displayed promising applications in the field of pharmaceutical wastewater purification.