Bimetallic Fe-Mo modified N-doped carbon materials activating peroxymonosulfate for acetaminophen degradation: Synergistic effects of free radicals and electron transfer process.

This study aimed to synthesize a bimetallic Fe-Mo modified N-doped carbon material (FeMo@NCN) using a simple pyrolysis method. Structural and physical characterizations confirmed the successful incorporation of Fe and Mo into the catalyst. The FeMo@NCN/PMS system exhibited an excellent acetaminophen (ACE) degradation rate (kobs = 0.1232 min-1), which is 51 times higher than that of NCN/PMS system (kobs = 0.0024 min-1). Mechanistic analysis revealed that the Fe/Mo interaction, as well as the synergistic effects between Mo-N and Fe-N sites, facilitated the continuous generation of reactive oxygen species (ROS), including SO4•- and •OH. Specifically, Mo doping to promoted the regeneration of Fe2+, contributing to the recovery of catalytic activity and playing a key role in maintaining high degradation efficiency. Furthermore, electrochemical analysis demonstrated that the Fe and Mo doping significantly enhanced the electronic transfer properties of the material, revealing the existence of an electron transfer-based non-radical pathway. Additionally, FeMo@NCN exhibited remarkable stability across a wide pH range (3-9). The intermediate degradation products and degradation pathways of ACE were identified, and the toxicity of ACE and its degradation products were evaluated. This work provides new insights into improving the performance of carbon-based materials for efficient removal of refractory organic compounds in PMS systems.