Abstract
The electrochemistry of the Nb(V)/Nb(IV) redox couple in the KCl-K2NbF7 melt has been studied at 1073-1173 K on glassy carbon and platinum electrodes by transient electrochemical techniques. The diffusion coefficients of Nb(V) and Nb(IV) were determined by linear sweep voltammetry, chronopotentiometry and chronoamperometry. The values obtained by these methods at the different substrates are also in a good agreement. Diffusion coefficients decreased when niobium oxidation state increased, while the activation energies for diffusion increased. The standard rate constants of charge transfer (ks) on platinum and glassy carbon electrodes for Nb(V)/Nb(IV) redox couple were calculated on the basis of cyclic voltammetry data at a sweep rate 0.75 < v ≤ 2.0 V s-1, where a mixed diffusion and electron-transfer control was observed. It was found that ks increased with increasing temperature and values of ks obtained at platinum electrode were higher than at a glassy carbon electrode. The values of the standard rate constants testify that the redox process Nb(V) + e- ↔ Nb(IV) proceeds quasi-reversibly, mostly under diffusion control.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
