Highly Sensitive and Selective Chromium Oxide Nanoparticles Modified Carbon Paste Membrane Electrode to Determine Cr Concentration in Different Solutions

Chromium ions in the solution were electro-oxidized using a novel carbon paste electrode containing Cr₂O₃ nanoparticles. As a result of the modification, the voltammetric response of Cr-ion could be resolved into one well-defined peak. As a result, the quest-reversible mechanism was activated. Researchers investigated the electrode's kinetics between 20 and 30 degrees Celsius. In the redox process of Cr-ion oxidation, the voltammogram data indicated a rise in temperature that increased negative shift, which implied diffusion electron transfer. The Randles-Sevcik equation gave a diffusion coefficient of 1.9 x10^-3; the rate constant K was 0.3x10^-3; and According to the study, In the range of 2-10 ppm, the peak current of Cr-ion rose linearly with its concentration, thermodynamic and kinetic parameters was calculated such as ∆E, ∆H, ∆G and ∆S equal to -58.2, -4.9, -65.1 and 0.11 KJ/mol respectively.