Enhanced visible light photo-Fenton-like degradation of tetracyclines by expanded perlite supported FeMo3Ox/g-C3N4 floating Z-scheme catalyst

J Hazard Mater. 2022 Feb 15;424(Pt A):127387. doi: 10.1016/j.jhazmat.2021.127387. Epub 2021 Sep 30.

Abstract

In the conventional Fenton system, the relatively low efficiency of Fe (II) regeneration is a significant drawback. To address this shortcoming, a novel floating Z-scheme photo-Fenton catalyst FeMo3Ox/g-C3N4/EP was prepared by a facile dip-calcination method, in which iron and molybdenum oxides with mixed valence states (FeMo3Ox) and graphitic carbon nitride (g-C3N4) were loaded on the expanded perlite. The removal efficiencies reached the maximum at 98.0%, 93.1% and 97.1% for tetracycline, oxytetracycline and chlortetracycline, respectively, after 60 min dark adsorption and 60 min photo-Fenton process. The aid of dual ion (Fe and Mo) synergy system and photoreduction by Z-scheme photocatalyst enhanced the Fe (II) regeneration, resulting in the excellent performance. Radical scavenger experiment, electron spin resonance spectra (ESR) and X-ray photoelectron spectra (XPS) were used to confirm the mechanism of free radicals' formation and Fe/Mo redox cycling. ·OH, ·O2- and 1O2 played important roles in the pollutant's degradation, while the generation of ·O2- was enhanced due to the floatability in this system. The possible degradation pathways of TC were put forward according to the results of mass spectrum and Orbital-Weighted Fukui Function. Overall, this work provides new insights on the cooperation between iron-based mix oxides and semiconductor in the photo-Fenton system.

Keywords: Expanded perlite; FeMo(3)O(x)/g-C(3)N(4); Photo-Fenton; Photocatalysis; Tetracyclines; Z-scheme heterojunctions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aluminum Oxide
  • Catalysis
  • Hydrogen Peroxide*
  • Light
  • Silicon Dioxide
  • Tetracyclines*

Substances

  • Tetracyclines
  • Perlite
  • Silicon Dioxide
  • Hydrogen Peroxide
  • Aluminum Oxide