Abstract

Herein, a novel electrochemical hydrazine sensor has been successfully fabricated using N-doped carbon film-immobilized Au nanoparticles coated ZnO jungle on indium tin oxide (AuNPs@NC-ZnO/ITO) as working electrode. The AuNPs@NC-ZnO/ITO has been prepared by an in situ synthesis method through the following steps. Firstly, the ZnO jungle modified ITO was prepared by electrochemical deposition method. Then, zeolitic imidazolate framework-8 (ZIF-8) film was formed on the surface of ZnO jungle by wet-chemical method using ZnO jungle and 2-methylimidazole as Zn precursor and organic ligand, respectively. The loading AuNPs was performed by adsorption of Au³⁺into micropores of ZIF-8, followed by heat treatment under N₂ atmosphere, where the ZIF-8 converted into N-doped carbon and Au³⁺ converted into AuNPs embedded in N-doped carbon film. Most importantly, such AuNPs@NC-ZnO/ITO exhibited good electrocatalytic activity for the oxidation of hydrazine. The hydrazine sensor based on AuNPs@NC-ZnO/ITO showed linear detection range from 0.05 to 10 μM and detection limit of 4.1 nM at a signal-to-noise ratio of 3.

Graphical abstract