Highly sensitive hydrazine chemical sensor fabricated by modified electrode of vertically aligned zinc oxide nanorods

A highly sensitive, reliable and reproducible hydrazine chemical sensor was fabricated using vertically aligned ZnO nanorods (NRs) electrode. The low temperature hydrothermal process was adopted to synthesize the vertically aligned ZnO NRs on fluorine doped tin oxide (FTO) glass. The morphological characterizations revealed the vertical arrangement of highly dense ZnO NRs on FTO substrates. The ultraviolet diffused reflectance spectroscopy (UV-DRS) of aligned ZnO NRs electrode obtained the band gap of ∼3.29 eV which was close to that of bulk ZnO nanomaterials. The synthesized aligned ZnO NRs electrode was directly used to elucidate the chemical sensing performance towards the detection of hydrazine by simple current–voltage (I–V) characteristics. The aligned ZnO NRs electrode based hydrazine chemical sensor presented a significantly high sensitivity of ∼4.42446×10−5 A mM−1 cm−2 and the detection limit of ∼515.7 μM with a correlation coefficient (R) of ∼0.73297 and a short response time (10 s). The electrochemical analysis of vertically aligned ZnO NRs electrode in the presence of hydrazine showed the increased current with high height of anodic peak which confirmed the involvement of high electron transfer process via high electrocatalytic activity of the electrode.