The Influence of Sodium Tungstate Concentration on the Electrode Reactions at Iron–Tungsten Alloy Electrodeposition
Creators
- 1. Institute of Applied Physics, MD-2028 Chisinau, Moldova
- 2. Transnistrian State University Named after T.G. Shevchenko, MD-3300 Tiraspol, Moldova/Kostroma State University, 156005 Kostroma, Russia
- 3. Institute of Applied Physics, MD-2028 Chisinau, Moldova/Vilnius University, LT-03225 Vilnius, Lithuania
- 4. Vilnius University, LT-03225 Vilnius, Lithuania/JSC "Elektronikos perdirbimo technologijos", LT-06140 Vilnius, Lithuania
- 5. Institute of Applied Physics, MD-2028 Chisinau, Moldova/Transnistrian State University Named after T.G. Shevchenko, MD-3300 Tiraspol, Moldova
Description
The investigation of Fe-W alloys is growing in comparison to other W alloys with iron group metals due to the environmental and health issues linked to Ni and Co materials. The influence of Na2WO4 concentration in the range 0 to 0.5 M on bath chemistry and electrode reactions on Pt in Fe-W alloys’ electrodeposition from citrate electrolyte was investigated by means of rotating disk electrode (RDE) and cyclic voltammetry (CV) synchronized with electrochemical quartz crystal microbalance (EQCM). Depending on species distribution, the formation of Fe-W alloys becomes thermodynamically possible at potentials less than −0.87 V to −0.82 V (vs. Ag/AgCl). The decrease in electrode mass during cathodic current pass in the course of CV recording was detected by EQCM and explained. The overall electrode process involving Fe-W alloy formation may be described using formalities of mixed kinetics. The apparent values of kinetic and diffusion currents linearly depend on the concentration of Na2WO4. Based on the values of partial currents for Fe and W, it was concluded that codeposition of Fe-W alloy is occurring due to an autocatalytic reaction, likely via the formation of mixed adsorbed species containing Fe and W compounds or nucleation clusters containing both metals on the electrode surface
Files
coatings-11-00981.pdf
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