A RGO aerogel/TiO2/MoS2 composite photocatalyst for the removal of organic dyes by the cooperative action of adsorption and photocatalysis

Environ Sci Pollut Res Int. 2022 Feb;29(6):8980-8995. doi: 10.1007/s11356-021-16143-z. Epub 2021 Sep 8.

Abstract

A composite consisting of reduced graphene oxide aerogel/titanium dioxide/molybdenum disulfide (abbreviated as RGO aerogel/TiO2/MoS2) was developed for the removal of organic dyes from solution cooperatively by adsorption and photocatalytic degradation mechanisms. The composite was successfully synthesized by stepwise layered assembly integration, including sol-gel and physical vapor deposition (PVD) methods. The resulting multi-component composite material featured a high specific surface area (255.441 m2/g) containing a myriad of negatively charged carboxylate functional groups on the surface of the composite, which enabled the composite material to demonstrate a high removal efficiency of cationic dyes, such as rhodamine B, from solution. In addition, the composite featured optimal optical and photocatalytic properties for facilitating efficient photodegradation of the dye molecules, including a large absorbance in the visible light region and a fast transfer of photogenerated electron-hole pairs. Moreover, electron paramagnetic resonance (EPR) analysis and reactive oxygen species scavenging experiments confirmed that superoxide radicals (O2•-), holes (h+), and hydroxyl radicals (OH) were involved in photocatalytic degradation of the organic dyes.

Keywords: Absorption; MoS2; Photocatalysis; Physical vapor deposition; RGO aerogel; Visible light.

MeSH terms

  • Adsorption
  • Catalysis
  • Coloring Agents*
  • Graphite
  • Molybdenum*
  • Titanium

Substances

  • Coloring Agents
  • graphene oxide
  • titanium dioxide
  • Graphite
  • Molybdenum
  • Titanium