Effect of Fluoride on the Morphology and Electrochemical Property of Co(3)O(4) Nanostructures for Hydrazine Detection

In this paper, we systematically investigated the influence of fluoride on the morphology and electrochemical property of Co(3)O(4) nanostructures for hydrazine detection. The results showed that with the introduction of NH(4)F during the synthesis process of Co(3)O(4), both Co(CO(3))(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 Co(3)O(4), three Co(3)O(4) nanostructures that were respectively obtained from bare Co(CO(3))(0.5)(OH)·0.11H(2)O, Co(OH)F and Co(CO(3))(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 Co(3)O(4) nanostructures decreased with the increase in the fluoride contents of precursors. The more that dosages of NH(4)F were used, the higher crystallinity and smaller specific surface area of Co(3)O(4) was gained. Among these three Co(3)O(4) nanostructures, the Co(3)O(4) that was obtained from bare Co(CO(3))(0.5)(OH)·0.11H(2)O-based hydrazine sensor displayed the best performances, which exhibited a great sensitivity (32.42 μA·mM(−1)), a low detection limit (9.7 μΜ), 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 Co(3)O(4) nanostructures decreased with the increase in fluoride contents of precursors.