Separation and Purification Technology | 2021
Enhanced peroxymonosulfate decomposition into OH and 1O2 for sulfamethoxazole degradation over Se doped g-C3N4 due to induced exfoliation and N vacancies formation
Abstract
Abstract The development of low-cost and facile synthesized metal-free peroxymonosulfate (PMS) activation catalysts is paramount important for the practical remediation of organic pollution caused by antibiotics. Graphitic carbon nitride (g-C3N4) as a promising alternative, to improve its PMS activation performance, we proposed an efficient method to prepare exfoliated Se doped g-C3N4 (Se-g-C3N4) with 0.095\xa0wt% Se and more exposed reactive N vacancies through the thermal polycondensation of melamine and Se powder at 550 ℃. The results proved that 93.0% of sulfamethoxazole (SMX) can be degraded over Se-g-C3N4 with PMS in 180\xa0min, and the corresponding degradation rate constant of 0.0149\xa0min−1 was even 4-fold higher than that of bulk g-C3N4 (0.0039\xa0min−1). It was found that more 1O2 was generated and OH was further identified because of the enhanced PMS self-decomposition process, especially PMS reduction via electron transfer from Se-g-C3N4. The introduction of Se atom in g-C3N4 structure not only induced the formation of nitrogen vacancies to modulate the electron distribution of g-C3N4, but also favored the exfoliation of inter-facial stacking to increase the exposure of active sites due to the large atomic radius of Se. Hence, this work offered a new strategy for improving the PMS activation performance of g-C3N4 by regulating its electron deficiency and exposing more reactive N vacancies simultaneously.