VIS-active TiO2 films decorated by expanded graphite: impact of the exfoliation time on the photocatalytic behaviour

Environ Technol. 2024 Apr;45(10):2022-2033. doi: 10.1080/09593330.2022.2163708. Epub 2023 Jan 11.

Abstract

TiO2/C nanocomposite films were applied on water treatment. Expanded graphite nanosheets (EG) were obtained by UVC-assisted liquid-phase exfoliation technique, without the addition of acids, surfactants, or aggressive oxidizing agents, which characterizes the process as an eco-friendly method. The carbon nanosheets were synthesized directly from graphite bulk at different times and deposited on TiO2 films surface by airbrush spray coating method, forming a TiO2/C heterojunction. The increase in the exfoliation time promoted a more efficient photocatalytic dye removal under visible light. Morphological modifications, changes in the electronic structure, and wide range of light absorption were observed from the TiO2/C heterojunction formation. The results showed that hybrid TiO2/C supported photocatalyst is a promise alternative for practical photocatalytic applications under sunlight.

Keywords: Expanded graphite; TiO2; heterojunction; liquid-phase exfoliation; photocatalysis.

MeSH terms

  • Graphite* / chemistry
  • Nanocomposites* / chemistry
  • Sunlight
  • Titanium / chemistry

Substances

  • Graphite
  • Titanium