Visible-light-induced Ag/BiVO4 semiconductor with enhanced photocatalytic and antibacterial performance

Nanotechnology. 2018 Feb 9;29(6):064001. doi: 10.1088/1361-6528/aaa052.

Abstract

An Ag-loaded BiVO4 visible-light-driven photocatalyst was synthesized by the microwave hydrothermal method followed by photodeposition. The photocatalytic performance of the synthesized samples was evaluated on a mixed dye (methylene blue and rhodamine B), as well as bisphenol A in aqueous solution. Similarly, the disinfection activities of synthesized samples towards the Gram-negative Escherichia coli (E. coli) in a model cell were investigated under irradiation with visible light (λ ≥ 420 nm). The synthesized samples have monoclinic scheelite structure. Photocatalytic results showed that all Ag-loaded BiVO4 samples exhibited greater degradation and a higher mineralization rate than the pure BiVO4, probably due to the presence of surface plasmon absorption that arises due to the loading of Ag on the BiVO4 surface. The optimum Ag loading of 5 wt% has the highest photocatalytic performance and greatest stability with pseudo-first-order rate constants of 0.031 min-1 and 0.023 min-1 for the degradation of methylene blue and rhodamine B respectively in a mixture with an equal volume and concentration of each dye. The photocatalytic degradation of bisphenol A reaches 76.2% with 5 wt% Ag-doped BiVO4 within 180 min irradiation time. Similarly, the Ag-loaded BiVO4 could completely inactivate E. coli cells within 30 min under visible light irradiation. The disruption of the cell membrane as well as degradation of protein and DNA exhibited constituted evidence for antibacterial activity towards E. coli. Moreover, the bactericidal mechanisms involved in the photocatalytic disinfection process were systematically investigated.

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Benzhydryl Compounds / chemistry
  • Bismuth / pharmacology*
  • Catalysis / radiation effects
  • Escherichia coli / drug effects
  • Escherichia coli / radiation effects
  • Escherichia coli / ultrastructure
  • Light*
  • Methylene Blue / chemistry
  • Microbial Sensitivity Tests
  • Microbial Viability / drug effects
  • Phenols / chemistry
  • Photoelectron Spectroscopy
  • Photolysis / radiation effects
  • Rhodamines / chemistry
  • Semiconductors*
  • Silver / pharmacology*
  • Spectrophotometry, Ultraviolet
  • Spectroscopy, Fourier Transform Infrared
  • Spectrum Analysis, Raman
  • Vanadates / pharmacology*
  • X-Ray Diffraction

Substances

  • Anti-Bacterial Agents
  • Benzhydryl Compounds
  • Phenols
  • Rhodamines
  • bismuth vanadium tetraoxide
  • Silver
  • Vanadates
  • rhodamine B
  • bisphenol A
  • Methylene Blue
  • Bismuth