Antibiotic degradation via synergistic oxidation: Zero - valent iron enhanced carbon - based catalyst activating peroxymonosulfate

Iron-based heterogenous catalysts play an important role in Fenton-like reactions, but their practical application is hindered by complex synthetic procedures and limited comprehension of reaction mechanisms. A straightforward impregnation and pyrolysis method was devised to synthesize a zero-valent iron (ZVI) modified carbon-based catalyst which significantly boosts PMS activation to degradation of tetracycline hydrochloride (TCH), more importantly, it elucidated the correlation between the electronic structure and the production of non-radical reactive oxygen species (ROS). The optimized catalyst demonstrates exceptional performance, achieving 97 % removal of TCH within 30 min, with a remarkable apparent rate constant (k_obs) of 0.1962 min⁻¹, outperforming the pristine carbon catalyst by 11-fold. Mechanistic investigations reveal that the incorporation of ZVI facilitates redox cycling with PMS, thereby boosting the generation of diverse ROS. Theoretical calculations reveal that both radical and non-radical pathways synergistically enhance catalytic activity. This work presents a cost-effective and scalable approach to designing high-performance carbon-based catalysts for PMS activation, providing valuable insights into the development of sustainable water purification technologies for emerging contaminants. © 2026 Elsevier Ltd.