Enhanced sulfamethazine detoxification by a novel BiOCl (110)/NrGO/BiVO4 heterojunction

Environ Res. 2023 Sep 1:232:116351. doi: 10.1016/j.envres.2023.116351. Epub 2023 Jun 15.

Abstract

The emerging contaminants removal from the environment has recently been raised concerns due to their presence in higher concentrations. Over usage of emerging contaminant such as sulfamethazine poses serious threat to the aquatic and human health as well. This study deals with rationally structured a novel BiOCl (110)/NrGO/BiVO4 heterojunction which is used to detoxify sulfamethazine (SMZ) antibiotic efficiently. The synthesised composite was well characterized and the morphological analysis evidenced the formation of heterojunction consisted of nanoplates BiOCl with dominant exposed (110) facets and leaf like BiVO4 on NrGO layers. Further results revealed that the addition of BiVO4 and NrGO tremendously increased the photocatalytic degradation efficiency of BiOCl with the rate of 96.9% (k = 0.01783 min-1) towards SMZ within 60 min of visible light irradiation. Furthermore, heterojunction energy-band theory was employed to determine the degradation mechanism of SMX in this study. The larger surface area of BiOCl and NrGO layers are believed to be the reason for higher activity which facilitates the excellent charge transfer and improved light absorption. In addition, SMZ degradation products identification was carried out by LC-ESI/MS/MS to determine the pathway of degradation. The toxicity assessment was studied using E. coli as a model microorganism through colony forming unit assay (CFU), and the results indicated a significant reduction in biotoxicity was observed in 60 min of degradation process. Thus, our work gives new methods in developing various materials that effectively treat emerging contaminants from the aqueous environment.

Keywords: BiOCl; Detoxification; Emerging contaminants; Photocatalysis; Sulfamethazine.

MeSH terms

  • Bismuth / analysis
  • Catalysis
  • Escherichia coli
  • Humans
  • Sulfamethazine* / toxicity
  • Tandem Mass Spectrometry
  • Water Pollutants, Chemical* / analysis
  • Water Pollutants, Chemical* / toxicity

Substances

  • Sulfamethazine
  • Bismuth
  • Water Pollutants, Chemical