Efficient hydrazine electrochemical sensor based on PANI doped mesoporous SrTiO3 nanocomposite modified glassy carbon electrode

Abstract

Herein, an electrochemical approach was developed for the rapid and selective determination of hydrazine using 5% polyaniline (PANI)-doped mesoporous SrTiO3 nanocomposite modified glassy carbon electrode (GCE). The nanocomposite was synthesized by a modified sol-gel procedure using F127 structure mediator agent to obtain mesoporous SrTiO3 followed by an ultra-sonication technique to produce the final PANI doped SrTiO3. Various characterization tools, namely, XRD, XPS, FE-SEM and HR-TEM confirmed the successful formation of the nanocomposite and revealed cubic perovskite structure with d-spacing value 2.70 Å for mesoporous SrTiO3. Cyclic voltammetry and electrochemical impedance spectroscopy measurements exhibited higher electrocatalytic performance of the PANI/SrTiO3 nanocomposite compared to either pure SrTiO3 or unmodified GCE. The hydrazine oxidation reaction follows the first-order diffusion-controlled kinetics with a transfer coefficient value 0.65 obtained from Tafel plot analysis. Linear sweep voltammetry (LSV) and amperometric (i-t) techniques revealed that the PANI/SrTiO3 nanocomposite modified GCE exhibited remarkable sensitivity; 0.2128 μAμM−1 cm−2 over the concentration range 0.2–3.56 mM (LSV) and 0.2438 μAμM−1 cm−2 over the concentration range 16–58 μM (amperometry) with a rapid response time < 10s. The limit of detection (LOD) was estimated to be 1.09 μM and 0.95 μM at (S/N = 3) for LSV and amperometric technique, respectively. Additionally, the modified electrode demonstrated excellent anti-interfering ability in the presence of various common active species as well as exhibited good operational stability and sutability for the real sample analysis. Such developed PANI/SrTiO3 nanocomposite represents an excellent electro-catalyst for efficient detection and quantification of hydrazine by the electrochemical approach.