N-doped catalysts built by iron-based metal–organic framework efficiently activated peroxymonosulfate for the tetracycline degradation

•Successfully prepared N-doped catalysts built by iron-based metal–organic framework.•Explored the different effects of different types of N sources on the same catalyst.•The addition of N improved the stability and dispersion of the metal–organic frame. Tetracycline, one of the most commonly used antibiotics, has emerged as a critical concern in water pollution treatment. N-doped iron-based catalysts were prepared by one-step pyrolysis with MIL-101 (Fe) as precursors in this study. The effects of doping ratio, material dosage, anions and other factors on the degradation efficiency of tetracycline were investigated. In best conditions, the removal rate of tetracycline has reached 91%, which was attributed to the synergistic effect of free radical (i.e., SO4•−, •OH) and non free radical pathways (i.e., 1O2). And the ion leaching of N doped catalysts was investigated. The iron ion leaching was maintained at a relatively low level. Then, LC-MS was used to study the pathway of tetracycline degradation. ECOSAR assessments had demonstrated that tetracycline and its intermediates exhibited significantly reduced levels of acute toxicity, developmental toxicity, and mutagenicity. These studies indicated that the derivative of N-doped iron-based MOFs was a highly promising, environmentally friendly catalyst for practical wastewater treatment applications.