Zeolitic imidazolate framework derived porous ZnO/Co3O4 incorporated with gold nanoparticles as ternary nanohybrid for determination of hydrazine

Abstract

A sensing platform based on porous ZnO/Co3O4 is introduced for determination of hydrazine in alkaline media. The bimetallic oxides were prepared by calcination of bimetallic zeolitic imidazolate framework (Zn/CoZIF) as a sacrificial template. Zn/CoZIF and ZnO/Co3O4 were characterized via several techniques. The porous ZnO/Co3O4 was utilized to modify glassy carbon electrode (ZnO/Co3O4/GCE), followed by immobilization of Au nanoparticles (NPs) on its surface to prepare Au/ZnO/Co3O4/GCE. The electrode exhibited two linear ranges of 2–1900 μM and 1900–8500 μM with sensitivity of 0.058 and 0.048 μA μM−1 for determination of hydrazine in aqueous solution. The sensor showed remarkable lower oxidation potential and limit of detection rather than ZnO/Co3O4/GCE. Furthermore, the sensor displayed acceptable selectivity toward oxidation of hydrazine in the presence of some interfering species. The results confirm that Au/ZnO/Co3O4/GCE can be considered as sensitive and reliable sensor toward the oxidation of hydrazine due to the porous structure of ZnO/Co3O4, high conductivity of Au NPs, and the synergic effect among the constituents.