Electrochemical behavior of NH4VO3 in glyceline DES studied by cyclic voltammetry method

In the present work, the redox behavior of vanadate ion in deep eutectic solvent (DES) was studied via cyclic voltammetry (CV) method where glyceline DES and NH4VO3 were used as electrolyte and the source of + 5 vanadium ions respectively. The CV showed a quasi-reversible redox couple pattern of + 5 to + 4 vanadium ions in glyceline DES. Analysis by UV-Vis revealed the presence of + 3 vanadium ions at lambda(max) 545 nm. The glyceline DES does not only act as a solvent but also as a reducing agent by chemically reducing + 4 vanadium ions to the most stable oxidation state of + 3. Temperature dependence study of vanadate ion in glyceline DES showed that the peak current increased with temperature which enhances the reaction kinetics. In addition, the conductivity of NH4VO3 in glyceline DES improved remarkably with temperature, whereas its viscosity declined. Moreover, the R-s and R-ct values decreased with increasing temperature.