Assembly of Maghemite Nanoparticles Into Particulate Nanosheets and Their Application in Wastewater Treatment

J Nanosci Nanotechnol. 2015 Jul;15(7):5384-90. doi: 10.1166/jnn.2015.9755.

Abstract

The maghemite particulate nanosheets (MPNs) are prepared in solvothermal system by connecting the nanoparticles in two-dimension. The interconnected MPNs sustain a mesopores structure with a high accessible surface area of 164 m2/g, and have a high performance for Cr6+ adsorption. The Cr6+ removal process fit with Langmuir adsorption model with an adsorption capacity of 20.41 mg/g. The purified solution could reach a residual concentration of 0.002 mg/L for MPNs, which is much less than the concentration in the solution of 0.249 mg/L when the nanoparticles are used. The synthesized MPNs with a saturation magnetization of 70.51 emu/g at room temperature can be easily collected and separated by an external magnet in liquid. Exchange coupling and shape anisotropy are the main reason for the higher Ms of MPNs. The unique structure with large surface area and high saturation magnetization make the MPNs favourable for the application of magnetic separation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromates / chemistry*
  • Ferric Compounds / chemistry*
  • Nanoparticles / chemistry*
  • Wastewater / chemistry*
  • Water Purification*

Substances

  • Chromates
  • Ferric Compounds
  • Waste Water
  • ferric oxide