Enhanced peroxymonosulfate activation for Orange I degradation by g-C3N4/AgFeO2 composite in water

The construction of heterogeneous catalysts with high efficiency is significant for the degradation of persistent contaminants. Herein, the g-C3N4/AgFeO2 composite was fabricated and its composition, morphology and structure were systematically characterized. g-C3N4/AgFeO2 exhibited boosting peroxymonosulfate (PMS) catalytic performance on the degradation of Orange I (OI) than pure AgFeO2. It was optimized that the elimination of OI could be enhanced to 91%, with a kinetic rate of 0.076 min−1. Such enhancement was attributed to the increment of low-valent metal species (Ag0/Ag+, Fe2+/Fe3+) on AgFeO2 surface after coupling with g-C3N4, additionally, the synergy of g-C3N4 and AgFeO2 endowed the g-C3N4/AgFeO2 composite with higher conductivity and more electron transfer, thereby promoting effective PMS decomposition. The leaching of metal ions in the g-C3N4/AgFeO2/PMS system was suppressed, which brought superior reusability and stability. It was verified that 1O2、O2•-、SO4•- and •OH acting as the key reactive oxygen species contributed to the OI removal. Our findings provided valuable insights into the design of efficient and stable g-C3N4-based organometallic composites for advanced oxidation processes.