Effect of Fluoride on the Morphology and Electrochemical Property of Co3O4 Nanostructures for Hydrazine Detection

In this paper, we systematically investigated the influence of fluoride on the morphology and electrochemical property of Co3O4 nanostructures for hydrazine detection. The results showed that with the introduction of NH4F during the synthesis process of Co3O4, both Co(CO3)(0.5)(OH)0.11H(2)O and Co(OH)F precursors would be generated. To understand the influence of F on the morphology and electrochemical property of Co3O4, three Co3O4 nanostructures that were respectively obtained from bare Co(CO3)(0.5)(OH)0.11H(2)O, Co(OH)F and Co(CO3)(0.5)(OH)0.11H(2)O mixtures and bare Co(OH)F were successfully synthesized. The electrochemical tests revealed the sensing performance of prepared Co3O4 nanostructures decreased with the increase in the fluoride contents of precursors. The more that dosages of NH4F were used, the higher crystallinity and smaller specific surface area of Co3O4 was gained. Among these three Co3O4 nanostructures, the Co3O4 that was obtained from bare Co(CO3)(0.5)(OH)0.11H(2)O-based hydrazine sensor displayed the best performances, which exhibited a great sensitivity (32.42 AmM-1), a low detection limit (9.7 M), and a wide linear range (0.010-2.380 mM), together with good selectivity, great reproducibility and longtime stability. To the best of our knowledge, it was revealed for the first time that the sensing performance of prepared Co3O4 nanostructures decreased with the increase in fluoride contents of precursors.