Ultrathin nanosheet-assembled accordion-like Ni-MOF for hydrazine hydrate amperometric sensing.

The ultrathin 2D metal-organic framework structure effectively increases the metal sites of the active molecules and endows Ni-MOF with good current sensing performance. The ultrathin 2D nanosheet Ni-MOF assemblies have been successfully synthesized by using (Ni3(OH)2(C8H4O4)2(H2O)4)·2H2O as the molecular formula. The sensor performance of Ni-MOF assemble was investigated by amperometric method. The resulting products are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electric signal generated by the electrochemical reaction on the electrode surface indicates that the assemble of Ni-MOF with ultrathin folded-like structure and special aggregation state has high electrocatalytic performance. In the detection of hydrazine hydrate, Ni-MOF assemble shows good stability, low detection limit (0.23 nm), and high selectivity in the range of 0.5 μM to 8.0 mM at a voltage of 0.25 V. This study provides a new idea for the application of MOF assemble in hydrazine hydrate sensor. Graphical abstract Schematic of illustration of the synthesis of the Ni-MOF and the Ni-MOF applied for catalyzing N2H4.