Sensitive amperometric determination of hydrazine using a carbon paste electrode modified with silver-doped zeolite L nanoparticles

Abstract

Silver-loaded nanozeolite-L-modified carbon paste electrode (Ag/L-CPE) was used as a novel sensing platform for enhanced electrocatalytic oxidation and determination of hydrazine. Zeolite L nanoparticles were synthesized via hydrothermal approach and then characterized using various techniques such as X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electronic microscopy (SEM) and Brunauer-Emmett-Teller (BET). Silver-exchanged nanozeolite L (Ag/L) was prepared and mixed with carbon paste to prepare the modified electrode. Cyclic voltammetry studies revealed the high performance of Ag/L-CPE for electrocatalytic oxidation of hydrazine. Two linear ranges were detected in the amperometric detection of hydrazine. The first range was from 10 μM to 0.4 mM with sensitivity of 103.13 μA mM-1 and the second one was from 0.4 to 4 mM with sensitivity of 58.131 μA mM-1. The response time and detection limit (S/N = 3) of this sensor were determined to be 2 s and 1.5 μM, respectively. The unique porous structure of nanozeolite L offers a promising catalyst support candidate for efficient electrochemical sensing of hydrazine. The sensor exhibited appreciable repeatability, reproducibility and stability, and was able to detect hydrazine in the presence of even 500-fold excess concentrations of interfering species. Also, the sensor was used to determine hydrazine concentration in water samples with satisfactory results.