Abstract
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•A novel α-Fe2O3/CPANI nanocomposite is used as an efficient hydrazine chemical sensor.•A remarkable sensitivity of 1.93mAμM−1cm−2 with a very low LOD 0.153μM.•A wide linear range (0.2–40μM) with a R2=0.9983 and amperometric response time <12s.•The electrocatalytic reaction obeys first order kinetics with a diffusion dominated process.•α-Fe2O3/CPANI modified electrode exhibits electrochemical stability and high selectivity.
Fabrication of efficient chemical sensors is a prime strategy for detecting trace levels of environmental species, but predominantly limited by slow response time, relatively low sensitivity and poor selectivity. Here, we demonstrate, for the first time, the synthesis of a novel nanocomposite of α-Fe2O3/crosslinked polyaniline (α-Fe2O3/CPANI) via a simultaneous gelation and polymerization process. The newly prepared α-Fe2O3/CPANI nanocomposite was employed as an efficient hydrazine chemical sensor with high sensitivity and selectivity. The XRD, XPS and HR-TEM results confirmed the presence of PANI and revealed a well-crystalline, structurally uniform crystals of rhombohedral α-Fe2O3 phase with particle sizes <50nm and distinctly lattice fringes of 3.7Å. The electrochemical detection of hydrazine was conducted at α-Fe2O3/CPANI modified glassy carbon electrode (GCE) by the cyclic voltammetry and amperometry techniques and compared with bare GCE or pure α-Fe2O3. Comparing to bare GCE or pure α-Fe2O3, the α-Fe2O3/CPANI nanocomposite modified GCE shows a superior sensing performance, leading to a remarkable sensitivity of 1.93μAμM−1cm−2, a very low limit of detection (LOD) of 0.153μM at (S/N=3), a wide linear range of hydrazine concentrations from 0.2μM to 40μM, with a correlation coefficient (R2)=0.9983 and a response time <12s. Additionally, the present α-Fe2O3/CPANI modified electrode exhibits electrochemical stability and high selectivity as a negligible cross-sensitivity to common bio-active interfering species and several metal ions was observed. Furthermore, the electrocatalytic reaction obeys the first order kinetics with respect to hydrazine concentration with a diffusion dominated process. Such a novel nanocomposite of α-Fe2O3/CPANI represents a proper electrode material for highly efficient detection of hydrazine by electrochemistry.