In-situ insertion of carbon nanotubes into metal-organic frameworks-derived alpha-Fe2O3 polyhedrons for highly sensitive electrochemical detection of nitrite

Achieving highly sensitive electrochemical detection of nitrite for the control of nitrite contamination is a constant challenge, therefore, exploring hierarchical nanostructured materials for electrochemical detection with high activity is a vital importance. In the present study, we prepared the highly ordered MOFs-derived alpha-Fe2O3/CNTs hybrids through in situ insertion of carbon nanotubes into MIL-101 (Fe) and their subsequent calcination for electrochemical detection of nitrite. MOFs-derived alpha-Fe2O3 polyhedrons are attached on the surface of CNTs tightly, forming hierarchical hybrids with interconnected building blocks. The in situ insertion of CNTs in the novel hybrids shortens the electron-transfer distance between the alpha-Fe2O3 and CNTs, which makes alpha-Fe2O3 become highly active for oxidation of nitrite. The prepared sensor demonstrated excellent performances of nitrite detection with the limit of detection (LOD) as low as 0.15 mu M, the high sensitivity of 334 mu A mM(-1) cm(-2) and the wide linear range from 0.5 mu M to 4000 mu M. What's more, the prepared sensor displayed the prominent reproducibility and superior stability with excellent anti-interference ability, and then was successfully applied for the detection of nitrite in Tap water and Pond water. (C) 2018 Elsevier Ltd. All rights reserved.