Abstract
A sensing platform based on porous ZnO/Co_3O_4 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/Co_3O_4 were characterized via several techniques. The porous ZnO/Co_3O_4 was utilized to modify glassy carbon electrode (ZnO/Co_3O_4/GCE), followed by immobilization of Au nanoparticles (NPs) on its surface to prepare Au/ZnO/Co_3O_4/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/Co_3O_4/GCE. Furthermore, the sensor displayed acceptable selectivity toward oxidation of hydrazine in the presence of some interfering species. The results confirm that Au/ZnO/ Co_3O_4/GCE can be considered as sensitive and reliable sensor toward the oxidation of hydrazine due to the porous structure of ZnO/Co_3O_4, high conductivity of Au NPs, and the synergic effect among the constituents.
NSTL
Elsevier