Novel Fenton process of Co-catalyst Co9S8 quantum dots for highly efficient removal of organic pollutants

Chemosphere. 2021 May:270:128648. doi: 10.1016/j.chemosphere.2020.128648. Epub 2020 Oct 19.

Abstract

Advanced oxidation processes (AOPs) have been widely accepted as an efficient and promising strategy for treating organic pollutants, is mainly dominated by hydroxyl radicals (•OH); however, its further practical application has been hindered by its low decomposition rate of H2O2. Hence, for the first time, we propose an eco-friendly and facile synthesis methodology synthesize water-soluble Co9S8 quantum dots (QDs) derived from commercial cobalt disulfide (CoS2), which can serve as excellent co-catalysts to dramatically enhance the decomposition rate of H2O2. It is demonstrated that the conversion rate of H2O2 into •OH is ca. 80.02% promoted by Co9S8 QDs, whereas the conventional Fenton process is ca. 34.9%. The result shows that unsaturated edged S atoms on the surface of Co9S8 play a pivotal role in this enhancement, where the number of protons will react with sulfur atoms to form H2S and expose reductive metallic active sites to accelerate the Fe3+/Fe2+ conversion. In addition, to tackle the issue for difficult recovery of liquid quantum dots, the magnetic Co9S8 QDs/Fe3O4 nanoparticles are particularly synthesized, which show excellent performance for degradation of 20 mg/L Rhodamine B (RhB). Moreover, the TOC degradation rate can remain stable at 80% even after five cycles. It is expected that this work will provide a new pathway of thinking in the Fenton process and impulse the usage of liquid quantum dots in practical AOPs application.

Keywords: Co(9)S(8) QDs; Co-catalytic; Fenton process; Recovery; Transition metal disulfides.

MeSH terms

  • Catalysis
  • Environmental Pollutants*
  • Hydrogen Peroxide
  • Piperidines
  • Quantum Dots*

Substances

  • Environmental Pollutants
  • Piperidines
  • S(8)
  • Hydrogen Peroxide