Lignosulfonate-Assisted In Situ Deposition of Palladium Nanoparticles on Carbon Nanotubes for the Electrocatalytic Sensing of Hydrazine

Abstract

This paper presents a novel modified electrode for an amperometric hydrazine sensor based on multi-walled carbon nanotubes (MWCNTs) modified with lignosulfonate (LS) and decorated with palladium nanoparticles (NPds). The MWCNT/LS/NPd hybrid was characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The electrochemical properties of the electrode material were evaluated using cyclic voltammetry and chronoamperometry. The results showed that GC/MWCNT/LS/NPd possesses potent electrocatalytic properties towards the electro-oxidation of hydrazine. The electrode demonstrated exceptional electrocatalytic activity coupled with a considerable sensitivity of 0.166 μA μM−1 cm−2. The response was linear from 3.0 to 100 µM L−1 and 100 to 10,000 µM L−1, and the LOD was quantified to 0.80 µM L−1. The efficacy of the modified electrode as an electrochemical sensor was corroborated in a study of hydrazine determination in water samples.

Fabrication and Characterization of an Electrochemical Platform for Formaldehyde Oxidation, Based on Glassy Carbon Modified with Multi-Walled Carbon Nanotubes and Electrochemically Generated Palladium Nanoparticles

“…To date, the modification of CNTs with PdNPs to obtain a CNT/PdNP composite has been achieved through various methods, including chemical reduction of Pd(II) ions with sodium borohydride [13,53], formaldehyde [52,54], and sodium citrate in an ethylene glycol solution [55]. Other techniques involve the thermal decomposition of palladium acetate [39], RF magnetron sputtering [56], and electrochemical reduction of the MWCNT/lignosulfonate-Pd 2+ composite [57]. However, these methods are timeconsuming and involve multiple steps that are challenging to control, consequently affecting the final properties and the cost of the obtained electrode materials.…”