A novel method to delaminate nitrate-intercalated MgAl layered double hydroxides in water and application in heavy metals removal from waste water

Chemosphere. 2018 Jul:203:281-290. doi: 10.1016/j.chemosphere.2018.03.166. Epub 2018 Mar 28.

Abstract

Nitrate-intercalated MgAl layered double hydroxide (LDH) was successfully delaminated in water by a facile and effective method upon reflux at 120 °C for 24 h followed by sonication at 40 °C for 5 h. This process is environmentally friendly since water is the only solvent used. The delaminated nanosheets were characterized by microscopic, spectroscopic, and particle size analyses. The delamination process successfully produced octahedron-shaped single-layer nanosheets 50-150 nm in size. X-ray photoelectron spectroscopy (XPS) data confirmed that the surface elements and their chemical status are consistent with the basic layer of MgAl LDH. The delaminated nanosheets displayed higher adsorption capacity for removing heavy metals from waste water than the original powdered LDH. After treating the waste water, a sharp and intense peak in the X-ray powder diffraction (XRD) pattern of the precipitate confirms the restacking of the LDH nanosheets.

Keywords: Delamination; Heavy metals removal; Mg–Al LDH; Waste water.

MeSH terms

  • Adsorption
  • Aluminum Hydroxide / analysis
  • Aluminum Hydroxide / chemistry*
  • Environmental Restoration and Remediation / methods*
  • Intercalating Agents / chemistry
  • Magnesium Hydroxide / analysis
  • Magnesium Hydroxide / chemistry*
  • Metals, Heavy / analysis
  • Nanostructures / chemistry
  • Nitrates / analysis
  • Photoelectron Spectroscopy
  • Sonication / methods
  • Wastewater / analysis
  • Wastewater / chemistry*
  • Water Pollutants, Chemical / analysis
  • Water Pollutants, Chemical / chemistry*
  • Water Purification / methods*
  • X-Ray Diffraction

Substances

  • Intercalating Agents
  • Metals, Heavy
  • Nitrates
  • Waste Water
  • Water Pollutants, Chemical
  • Aluminum Hydroxide
  • Magnesium Hydroxide