Electrochemical behavior of an indenedione derivative electrodeposited on a renewable sol-gel derived carbon ceramic electrode modified with multi-wall carbon nanotubes: Application for electrocatalytic determination of hydrazine

A novel modified carbon ceramic electrode (CCE) containing multi-wall carbon nanotubes (MWCNTs) was fabricated by a sol-gel technique. The prepared MWCNT-CCE was modified by the electrodeposition of an indenedione derivative. The indenedione modified MWCNT-CCE (IMWCNT-CCE) shows one pair of peaks with surface confined characteristics. According to the theoretical model of Laviron, estimations were made in different pHs of the surface charge transfer rate constant, k_s, and the charge transfer coefficient, α, for electron transfer between the indenedione derivative and MWCNT-CCE. The modified electrode shows a highly catalytic activity toward hydrazine electrooxidation at a wide pH range (5-9). The kinetic parameters such as the electron transfer coefficient, α, the heterogeneous rate constant, k′, and the exchange current of hydrazine at the IMWCNT-CCE were calculated as 0.29 ± 0.01, 2.7(±0.3) × 10⁻³ cm s⁻¹ and 0.17 ± 0.03 μA, respectively. Also, the modified electrode shows an excellent analytical performance for voltammetric determination of hydrazine. Differential pulse voltammetry (DPV) exhibits two linear dynamic ranges, 0.6-8.0 μM and 8.0-100.0 μM, and a lower detection limit of 0.29 μM for hydrazine. Finally, the practical analytical utility is illustrated by differential pulse voltammetric determination of hydrazine in auxiliary cooling water at IMWCNT-CCE and the accuracy of the results is verified in comparison with those obtained from the standard ASTM method.