Amoxicillin photodegradation under visible light catalyzed by metal-free carbon nitride: An investigation of the influence of the structural defects

J Hazard Mater. 2021 Jan 5:401:123713. doi: 10.1016/j.jhazmat.2020.123713. Epub 2020 Aug 19.

Abstract

Herein, the structural defects of metal-free polymeric carbon nitrides were controlled by making use of different precursors in their syntheses, i.e. melamine (CN-M) and thiourea (CN-T), as well as a 1:1 mixture of them (CN-1M:1 T). By controlling the structural defects, the electronic, morphological and chemical properties were modified. Additionally, the activities of synthesized PCNs were evaluated for amoxicillin photodegradation under visible light irradiation (16 mW cm-2). The results of photocatalytic tests showed that CN-T material has better efficiency (100 % removal within 48 h), which is directly related to the greater number of defects present in its structure with consequent improvement of electron-hole pairs separation efficiency. The CN-T material showed excellent stability with only 13 % decrease in its photocatalytic activity after the third cycle. A mechanism for amoxicillin degradation by CN-T was proposed based on the ESI-MS and the in situ EPR allied with spin trapping method investigations.

Keywords: Amoxicillin; Carbon nitrides; Metal-free; Photocatalysis; Visible region.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amoxicillin*
  • Catalysis
  • Graphite*
  • Light
  • Nitriles
  • Photolysis

Substances

  • Nitriles
  • cyanogen
  • Graphite
  • Amoxicillin