Fabrication of Hollow LDH nanocages using ZIF-67 template as superb adsorbent for anionic organic pollutant

Zeolitic imidazolate framework-67 (ZIF-67) was occupied as self-sacrifice template to fabricate hollow LDH nanocages, and the template was consumed during the formation of LDH nanocages. The nanocages composed of NiCo-LDH nanosheets maintained the dodecahedron shape of the ZIF-67 template. The resultant LDH nanocages were of large surface area and hollow porous structure and performed excellent in the adsorptive removal of Congo Red (CR). Influence of factors on the removal of CR was investigated and kinetic study and thermodynamic study were carried out to verify that the removal of CR was a chemisorption process. LDH nanocages after adsorption can be separated and regenerated through solvothermal method using ethanol, and the regenerated LDH nanocages can be recycling used and 89.3% removal of CR can still be reached in the fifth cycling.