Synergistic effect of the composite films formed by zeolitic imidazolate framework 8 (ZIF-8) and porous nickel films for enhanced amperometric sensing of hydrazine.

A novel ZIF-Ni composite film has been successfully prepared by a facile method involving the in situ deposition of ZIF-8 on a nickel porous film which is fabricated by selectively etching copper from a dense Ni/Cu alloy film. The nanostructures of the resulting ZIF-Ni composite films are carefully examined by a combination of scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray (EDX), and nitrogen adsorption-desorption. Cyclic voltammetric and amperometric studies show the enhanced electrocatalytic properties of the ZIF-Ni composite film electrodes toward hydrazine oxidation relative to the synergistic effect of ZIF-8 and porous Ni films. The application potential of the composite films as amperometric detectors is explored for the determination of hydrazine. A high sensitivity of 805.5 μA mM-1 for hydrazine detection with a low detection limit of 0.021 μM (S/N = 3) and a wide linear range from 2.5 μM to 28 mM are revealed for this new type of composite film as the detecting electrode. Moreover, the composite films exhibit excellent selectivity and remarkable stability for the oxidation of hydrazine. This can offer new opportunities for the fast and selective detection of hydrazine and provide a promising platform for sensor designs for hydrazine detection.